<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">JAMP</journal-id><journal-title-group><journal-title>Journal of Applied Mathematics and Physics</journal-title></journal-title-group><issn pub-type="epub">2327-4352</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/jamp.2015.37091</article-id><article-id pub-id-type="publisher-id">JAMP-57613</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  Existence and Multiple of Positive Solution for Nonlinear Fractional Difference Equations with Parameter
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Youji</surname><given-names>Xu</given-names></name><xref ref-type="aff" rid="aff1"><sub>1</sub></xref></contrib></contrib-group><aff id="aff1"><label>1</label><addr-line>Department of Mathematics, Northwest Normal University, Lanzhou, China</addr-line></aff><author-notes><corresp id="cor1">* E-mail:</corresp></author-notes><pub-date pub-type="epub"><day>30</day><month>06</month><year>2015</year></pub-date><volume>03</volume><issue>07</issue><fpage>757</fpage><lpage>760</lpage><history><date date-type="received"><day>31</day>	<month>March</month>	<year>2015</year></date><date date-type="rev-recd"><day>accepted</day>	<month>23</month>	<year>June</year>	</date><date date-type="accepted"><day>30</day>	<month>June</month>	<year>2015</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
   Let<inline-formula><inline-graphic xlink:href="dit_59ea5cf9-8897-47a8-bb1c-5c4408d739bb.png" xlink:type="simple"/></inline-formula>,<inline-formula><inline-graphic xlink:href="dit_21856fd0-987e-4767-8dbf-3135b2e60d60.png" xlink:type="simple"/></inline-formula>. We study the existence and multiple positive solutions of n-th nonlinear discrete fractional boundary value problem of the form <inline-formula><inline-graphic xlink:href="dit_20a42765-de9b-4329-9d3c-0064b46e7ba1.png" xlink:type="simple"/></inline-formula>By using a fixed-point theorem on cone, the parameter intervals of problem is established. 
 
</p></abstract><kwd-group><kwd>Fractional Difference Equations</kwd><kwd> Parameter Intervals</kwd><kwd> Positive Solution</kwd><kwd> Fixed-Point Theorem</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>There have been of great interest recently on fractional difference equations. It is caused by the development of the theory of fractional calculus and discrete fractional calculus, also by its applications, see [<xref ref-type="bibr" rid="scirp.57613-ref1">1</xref>]-[<xref ref-type="bibr" rid="scirp.57613-ref7">7</xref>]. We noted that most papers on discrete fractional difference equation are devoted to solvability of linear initial fractional difference equations [<xref ref-type="bibr" rid="scirp.57613-ref8">8</xref>] [<xref ref-type="bibr" rid="scirp.57613-ref9">9</xref>]. Recently, there are some papers dealing with the existence of solutions of nonlinear boundary value problems, we also refer the readers to [<xref ref-type="bibr" rid="scirp.57613-ref10">10</xref>] [<xref ref-type="bibr" rid="scirp.57613-ref11">11</xref>]. However, there are few papers consider parameter intervals of fractional difference boundary value problems. In the present work, our purpose is to the parameter intervals of the following fractional difference boundary value problem</p><disp-formula id="scirp.57613-formula279"><label>(1.1)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x6.png"  xlink:type="simple"/></disp-formula><disp-formula id="scirp.57613-formula280"><label>(1.2)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x7.png"  xlink:type="simple"/></disp-formula><p>where<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x8.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x9.png" xlink:type="simple"/></inline-formula>is an integer, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x10.png" xlink:type="simple"/></inline-formula>is continuous, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x11.png" xlink:type="simple"/></inline-formula>for <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x12.png" xlink:type="simple"/></inline-formula> and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x13.png" xlink:type="simple"/></inline-formula>. For<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x14.png" xlink:type="simple"/></inline-formula>, define<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x15.png" xlink:type="simple"/></inline-formula>.</p><p>F. M. Atici and P. W. E. [<xref ref-type="bibr" rid="scirp.57613-ref10">10</xref>] studied fractional difference boundary value problem</p><disp-formula id="scirp.57613-formula281"><label>(1.3)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x16.png"  xlink:type="simple"/></disp-formula><p>with the boundary value condition (1.2). By using Krasnosel’skii fixed point theorem under condition</p><p>(H1)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x17.png" xlink:type="simple"/></inline-formula>,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x18.png" xlink:type="simple"/></inline-formula>;</p><p>(H2)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x19.png" xlink:type="simple"/></inline-formula>, where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x19.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x20.png" xlink:type="simple"/></inline-formula> is a positive function, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x19.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x20.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x21.png" xlink:type="simple"/></inline-formula>is a non-negative function and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x19.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x20.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x21.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x22.png" xlink:type="simple"/></inline-formula></p><p>(H3)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x23.png" xlink:type="simple"/></inline-formula>, where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x23.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x24.png" xlink:type="simple"/></inline-formula> is a positive function, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x23.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x24.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x25.png" xlink:type="simple"/></inline-formula>is a non-negative function and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x23.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x24.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x25.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x26.png" xlink:type="simple"/></inline-formula></p><p>They get the following.</p><p>Theorem 1.1[<xref ref-type="bibr" rid="scirp.57613-ref10">10</xref>] Assume that conditions (H1) and (H2) are satisfied, then problem (1.1) and (1.2) has at least one solution. Assume that conditions (H1) and (H3) are satisfied, then problem (1.1) and (1.2) has at least one solution.</p><p>The following conditions will be used in the paper</p><p>(A1)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x27.png" xlink:type="simple"/></inline-formula>, where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x27.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x28.png" xlink:type="simple"/></inline-formula> is a positive function, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x27.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x28.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x29.png" xlink:type="simple"/></inline-formula>is continuous, and there exist <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x27.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x28.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x29.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x30.png" xlink:type="simple"/></inline-formula> such that<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x27.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x28.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x29.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x30.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x31.png" xlink:type="simple"/></inline-formula>;</p><p>(A2)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x32.png" xlink:type="simple"/></inline-formula>.</p></sec><sec id="s2"><title>2. Preliminaries</title><p>Recall the factorial polynomial <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula> where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula> denotes the special Gamma function and if <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x35.png" xlink:type="simple"/></inline-formula> for some<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x36.png" xlink:type="simple"/></inline-formula>, we assume the product is zero. We shall employ the convention that division at a pole yields zero. For arbitrary<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x37.png" xlink:type="simple"/></inline-formula>, define <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x38.png" xlink:type="simple"/></inline-formula> We also appeal to the convention that <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x33.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x34.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x39.png" xlink:type="simple"/></inline-formula></p><p>is a pole of the Gamma function and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula> is not a pole, then<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula>. Let<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x43.png" xlink:type="simple"/></inline-formula>and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x43.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x44.png" xlink:type="simple"/></inline-formula> defined on<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x43.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x45.png" xlink:type="simple"/></inline-formula>, Miller and Ross [<xref ref-type="bibr" rid="scirp.57613-ref12">12</xref>] have defined the <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x43.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x45.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x46.png" xlink:type="simple"/></inline-formula>-th fractional sum of <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x42.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x43.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x45.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x46.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x47.png" xlink:type="simple"/></inline-formula> by</p><disp-formula id="scirp.57613-formula282"><label>(2.1)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x48.png"  xlink:type="simple"/></disp-formula><p>where<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x49.png" xlink:type="simple"/></inline-formula>, also define the <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x49.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x50.png" xlink:type="simple"/></inline-formula>-th fractional difference</p><disp-formula id="scirp.57613-formula283"><graphic  xlink:href="http://html.scirp.org/file/57613x51.png"  xlink:type="simple"/></disp-formula><p>where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x52.png" xlink:type="simple"/></inline-formula> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x52.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x53.png" xlink:type="simple"/></inline-formula> with<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x52.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x53.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x54.png" xlink:type="simple"/></inline-formula>,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x52.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x53.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x54.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x55.png" xlink:type="simple"/></inline-formula>.</p><p>Lemma 2.1 [<xref ref-type="bibr" rid="scirp.57613-ref10">10</xref>] Let<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x56.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x56.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x57.png" xlink:type="simple"/></inline-formula>, the unique solution problem</p><disp-formula id="scirp.57613-formula284"><label>(2.2)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x58.png"  xlink:type="simple"/></disp-formula><p>is <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x59.png" xlink:type="simple"/></inline-formula> where</p><disp-formula id="scirp.57613-formula285"><label>(2.3)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x60.png"  xlink:type="simple"/></disp-formula><p>Lemma 2.2 [<xref ref-type="bibr" rid="scirp.57613-ref10">10</xref>] The Green’s function <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x61.png" xlink:type="simple"/></inline-formula> in Lemma 2.1 satisfies the following conditions:</p><p>(i) <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x62.png" xlink:type="simple"/></inline-formula>for <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x62.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x63.png" xlink:type="simple"/></inline-formula> and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x62.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x63.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x64.png" xlink:type="simple"/></inline-formula>;</p><p>(ii) <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x65.png" xlink:type="simple"/></inline-formula>for<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x65.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x66.png" xlink:type="simple"/></inline-formula>;</p><p>(iii) There exists a positive number <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x67.png" xlink:type="simple"/></inline-formula> such that for <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x67.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x68.png" xlink:type="simple"/></inline-formula></p><disp-formula id="scirp.57613-formula286"><label>(2.4)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x69.png"  xlink:type="simple"/></disp-formula><p>where</p><disp-formula id="scirp.57613-formula287"><label>(2.5)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/57613x70.png"  xlink:type="simple"/></disp-formula><p>In the rest of the paper, we will use the fixed point index theory in cones to deal with (1.1) and (1.2).</p><p>Lemma2.3 [<xref ref-type="bibr" rid="scirp.57613-ref12">12</xref>] Let <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula> be a Banach space, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x72.png" xlink:type="simple"/></inline-formula>be a cone, and suppose that <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x72.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x73.png" xlink:type="simple"/></inline-formula> are bounded open balls of <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x72.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x73.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x74.png" xlink:type="simple"/></inline-formula> centered at the origin with<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x72.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x73.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x74.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x75.png" xlink:type="simple"/></inline-formula>. Suppose further that <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x71.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x72.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x73.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x74.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x75.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x76.png" xlink:type="simple"/></inline-formula> is a completely continuous operator such that either</p><p>(i)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x77.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x77.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x78.png" xlink:type="simple"/></inline-formula>and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x77.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x78.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x79.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x77.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x78.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x79.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x80.png" xlink:type="simple"/></inline-formula>, or</p><p>(ii)<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x81.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x81.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x82.png" xlink:type="simple"/></inline-formula>and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x81.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x82.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x83.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x81.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x82.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x83.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x84.png" xlink:type="simple"/></inline-formula></p><p>holds, then <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x85.png" xlink:type="simple"/></inline-formula> has a fixed point in<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x85.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x86.png" xlink:type="simple"/></inline-formula>.</p><p>We will need the following notations. Let</p><disp-formula id="scirp.57613-formula288"><graphic  xlink:href="http://html.scirp.org/file/57613x87.png"  xlink:type="simple"/></disp-formula><p>Then <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x88.png" xlink:type="simple"/></inline-formula> is a Banach space with the norm <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x88.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x89.png" xlink:type="simple"/></inline-formula></p><p>So, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x90.png" xlink:type="simple"/></inline-formula>is a solution of (1.1) and (1.2) if, and only if <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x90.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x91.png" xlink:type="simple"/></inline-formula> is a fixed point of the operator <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x90.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x91.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x92.png" xlink:type="simple"/></inline-formula> defined by</p><disp-formula id="scirp.57613-formula289"><graphic  xlink:href="http://html.scirp.org/file/57613x93.png"  xlink:type="simple"/></disp-formula><p>Note<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula>, let <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula> be defined by (2.5) and define cones <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula> in <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula> by <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula> For some<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x99.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x99.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x100.png" xlink:type="simple"/></inline-formula>Since <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x99.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x100.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x101.png" xlink:type="simple"/></inline-formula> is finite dimensional, we have the <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x99.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x100.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x101.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x102.png" xlink:type="simple"/></inline-formula> is compact. Obviously,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x94.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x95.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x96.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x97.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x98.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x99.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x100.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x101.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x102.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x103.png" xlink:type="simple"/></inline-formula>.</p><p>Lemma 2.4 Suppose that conditions (A1) hold, and there exist two different positive numbers <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x104.png" xlink:type="simple"/></inline-formula> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x104.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x105.png" xlink:type="simple"/></inline-formula> such that</p><p><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x106.png" xlink:type="simple"/></inline-formula>where<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x106.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x107.png" xlink:type="simple"/></inline-formula>.</p><p>Then, problem (1.1), (1.2) has at least one positive solution <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x108.png" xlink:type="simple"/></inline-formula> such that<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x108.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x109.png" xlink:type="simple"/></inline-formula>.</p><p>Proof. We can suppose that<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x110.png" xlink:type="simple"/></inline-formula>. For<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x110.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x111.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x110.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x111.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x112.png" xlink:type="simple"/></inline-formula>, there is<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x110.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x111.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x112.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x113.png" xlink:type="simple"/></inline-formula>, then</p><disp-formula id="scirp.57613-formula290"><graphic  xlink:href="http://html.scirp.org/file/57613x114.png"  xlink:type="simple"/></disp-formula><p>these mains that for<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x115.png" xlink:type="simple"/></inline-formula>, there is<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x115.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x116.png" xlink:type="simple"/></inline-formula>. For<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x115.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x116.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x117.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x115.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x116.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x117.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x118.png" xlink:type="simple"/></inline-formula>, there is<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x115.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x116.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x117.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x118.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x119.png" xlink:type="simple"/></inline-formula>, then</p><disp-formula id="scirp.57613-formula291"><graphic  xlink:href="http://html.scirp.org/file/57613x120.png"  xlink:type="simple"/></disp-formula><p>these mains that for<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula>, there is<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula>. By using Lemma 2.3, there exist <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x123.png" xlink:type="simple"/></inline-formula> such that<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x123.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x124.png" xlink:type="simple"/></inline-formula>. This means that, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x123.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x124.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x125.png" xlink:type="simple"/></inline-formula>is a solution of problems (1.1), (1.2) and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x123.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x124.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x125.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x126.png" xlink:type="simple"/></inline-formula>. Also, because<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x121.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x122.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x123.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x124.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x125.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x126.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x127.png" xlink:type="simple"/></inline-formula>,</p><p>so <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula> for<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x129.png" xlink:type="simple"/></inline-formula>, taking into account that conditions(A1) and (A2) hold and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x129.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x130.png" xlink:type="simple"/></inline-formula>, we have that <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x129.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x130.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x131.png" xlink:type="simple"/></inline-formula> for<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x129.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x130.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x131.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x132.png" xlink:type="simple"/></inline-formula>, i.e. <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x128.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x129.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x130.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x131.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x132.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x133.png" xlink:type="simple"/></inline-formula>is a positive solution of (1.1), (1.2).</p></sec><sec id="s3"><title>3. Main Results</title><p>For some<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x134.png" xlink:type="simple"/></inline-formula>, denote <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x134.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x135.png" xlink:type="simple"/></inline-formula></p><p>By using Lemma 2.4, we get</p><p>Theorem 3.1 Assume that (A1) hold, and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x136.png" xlink:type="simple"/></inline-formula> and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x136.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x137.png" xlink:type="simple"/></inline-formula>, then, there exist<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x136.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x137.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x138.png" xlink:type="simple"/></inline-formula>, for every<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x136.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x137.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x138.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x139.png" xlink:type="simple"/></inline-formula>, problem (1.1) and (1.2) has at least two positive solutions.</p><p>Theorem 3.2 Assume that (A1) hold, and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x140.png" xlink:type="simple"/></inline-formula> or<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x140.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x141.png" xlink:type="simple"/></inline-formula>, then, for every<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x140.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x141.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x142.png" xlink:type="simple"/></inline-formula>, problem (1.1) and (1.2) has at least one positive solutions.</p><p>Theorem 3.3 Assume that (A1) hold, and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x143.png" xlink:type="simple"/></inline-formula> and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x143.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x144.png" xlink:type="simple"/></inline-formula>, then, for every<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x143.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x144.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x145.png" xlink:type="simple"/></inline-formula>, problem (1.1) and (1.2) has at least two positive solutions.</p><p>Theorem 3.4 Assume that (A1) and (A2) hold, and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x146.png" xlink:type="simple"/></inline-formula> or<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x146.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x147.png" xlink:type="simple"/></inline-formula>, then, for every<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x146.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x147.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/57613x148.png" xlink:type="simple"/></inline-formula>, problem (1.1) and (1.2) has at least one positive solutions.</p></sec><sec id="s4"><title>Acknowledgements</title><p>Author was supported by the NSF of Gansu Province (No. 2013GS08288).</p></sec><sec id="s5"><title>Cite this paper</title><p>Youji Xu, (2015) Existence and Multiple of Positive Solution for Nonlinear Fractional Difference Equations with Parameter. Journal of Applied Mathematics and Physics,03,757-760. doi: 10.4236/jamp.2015.37091</p></sec></body><back><ref-list><title>References</title><ref id="scirp.57613-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">Miller, K.S. and Ross, B. (1988) Fractional Difference Calculus. Proceedings of the International Symposium on Univalent Functions, Fractional Calculus and Their Applications, Nihon University, Koriyama, 139-152; Ellis Horwood Ser. Math. Appl., Horwood, Chichester, 1989.</mixed-citation></ref><ref id="scirp.57613-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">Agrawal, O.P. (2002) Formulation of Euler-Lagrange Equations for Fractional Variational Problems. Journal of Mathematical Analysis and Applications, 272, 368-379. http://dx.doi.org/10.1016/S0022-247X(02)00180-4</mixed-citation></ref><ref id="scirp.57613-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">Podlubny, I. (1999) Fractional Differential Equations. Academic Press, New York.</mixed-citation></ref><ref id="scirp.57613-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">Lakshmikantham, V. and Vatsala, A.S. (2008) Basic Theory of Fractional Differential Equations. Nonlinear Analysis: Theory, Methods &amp; Applications, 69, 2677-2682. http://dx.doi.org/10.1016/j.na.2007.08.042</mixed-citation></ref><ref id="scirp.57613-ref5"><label>5</label><mixed-citation publication-type="other" xlink:type="simple">Bai, Z. and Lü, H. (2005) Positive Solutions for Boundary Value Problem of Nonlinear Fractional Differential Equation. Journal of Mathematical Analysis and Applications, 311, 495-505. http://dx.doi.org/10.1016/j.jmaa.2005.02.052</mixed-citation></ref><ref id="scirp.57613-ref6"><label>6</label><mixed-citation publication-type="other" xlink:type="simple">Salem, H.A.H. (2009) On the Fractional Order m-Point Boundary Value Problem in Reflexive Banach Spaces and Weak Topologies. Journal of Computational and Applied Mathematics, 224, 567-572.  
http://dx.doi.org/10.1016/j.cam.2008.05.033</mixed-citation></ref><ref id="scirp.57613-ref7"><label>7</label><mixed-citation publication-type="other" xlink:type="simple">Atici, F.M. and Eloe, P.W. (2007) A Transform Method in Discrete Fractional Calculus. International Journal of Difference Equations, 2, 165-176.</mixed-citation></ref><ref id="scirp.57613-ref8"><label>8</label><mixed-citation publication-type="other" xlink:type="simple">Goodrich, C.S. (2010) Continuity of Solutions to Discrete Fractional Initial Value Problems. Computers and Mathematics with Applications, 59, 3489-3499. http://dx.doi.org/10.1016/j.camwa.2010.03.040</mixed-citation></ref><ref id="scirp.57613-ref9"><label>9</label><mixed-citation publication-type="other" xlink:type="simple">Atici, F.M. and Eloe, P.W. (2009) Initial Value Prob-lems in Discrete Fractional Calculus. Proceedings of the American Mathematical Society, 137, 981-989. http://dx.doi.org/10.1090/S0002-9939-08-09626-3</mixed-citation></ref><ref id="scirp.57613-ref10"><label>10</label><mixed-citation publication-type="other" xlink:type="simple">Atici, F.M. and Eloe, P.W. (2011) Two-Point Boundary Value Problems for Finite Fractional Difference Equations. Journal of Difference Equations and Applications, 17, 445-456. http://dx.doi.org/10.1080/10236190903029241</mixed-citation></ref><ref id="scirp.57613-ref11"><label>11</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Goodrich</surname><given-names> C.S. </given-names></name>,<etal>et al</etal>. (<year>2010</year>)<article-title>Solutions to a Discrete Right-Focal Fractional Boundary Value Problem</article-title><source> International Journal of Difference Equations</source><volume> 5</volume>,<fpage> 195</fpage>-<lpage>216</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.57613-ref12"><label>12</label><mixed-citation publication-type="other" xlink:type="simple">Guo, D. and Laksmikantham, V. (1988) Nonlinear Problems in Abstract Cones. Academic Press, London.</mixed-citation></ref></ref-list></back></article>