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   <ui>1029-242X-2010-960672</ui>
   <ji>1029-242X</ji>
   <fm>
      <dochead>Research Article</dochead>
      <bibl>
         <title>
            <p>On Ostrowski-Type Inequalities for Higher-Order Partial Derivatives</p>
         </title>
         <aug>
            <au ca="yes" id="A1"><snm>Changjian</snm><fnm>Zhao</fnm><insr iid="I1"/><email>chjzhao@163.com</email></au>
            <au id="A2"><snm>Cheung</snm><fnm>Wing-Sum</fnm><insr iid="I2"/><email>wscheung@hku.hk</email></au>
         </aug>
         <insg>
            <ins id="I1"><p>Department of Information and Mathematics Sciences, College of Science, China Jiliang University, Hangzhou 310018, China</p></ins>
            <ins id="I2"><p>Department of Mathematics, The University of Hong Kong, Pokfulam Road, Hong Kong</p></ins>
         </insg>
         <source>Journal of Inequalities and Applications</source>
         <issn>1029-242X</issn>
         <pubdate>2010</pubdate>
         <volume>2010</volume>
         <issue>1</issue>
         <fpage>960672</fpage>
         <url>http://www.journalofinequalitiesandapplications.com/content/2010/1/960672</url>
         <xrefbib><pubid idtype="doi">10.1155/2010/960672</pubid></xrefbib>
      </bibl>
      <history><rec><date><day>4</day><month>11</month><year>2009</year></date></rec><acc><date><day>14</day><month>1</month><year>2010</year></date></acc><pub><date><day>14</day><month>2</month><year>2010</year></date></pub></history>
      <cpyrt><year>2010</year><collab>The Author(s).</collab><note>This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</note></cpyrt>
      <abs>
         <sec>
            <st>
               <p/>
            </st>
            <p>We establish some new Ostrowski-type integral inequalities involving higher-order partial derivatives. As applications, we get some interrelated results. Our results provide new estimates on inequalities of this type.</p>
         </sec>
      </abs>
   </fm>
   <bdy>
      <sec>
         <st>
            <p>1. Introduction</p>
         </st>
         <p>The following inequality is well known in the literature as Ostrowski's integral inequality (see [<abbr bid="B1">1</abbr>, page 468]).</p>
         <p>Theorem 1.1. </p>
         <p>Let <inline-formula><graphic file="1029-242X-2010-960672-i1.gif"/></inline-formula> be a differentiable mapping on <inline-formula><graphic file="1029-242X-2010-960672-i2.gif"/></inline-formula> whose derivative <inline-formula><graphic file="1029-242X-2010-960672-i3.gif"/></inline-formula> is bounded on <inline-formula><graphic file="1029-242X-2010-960672-i4.gif"/></inline-formula> that is, <inline-formula><graphic file="1029-242X-2010-960672-i5.gif"/></inline-formula> then </p>
         <p>
            <display-formula id="M11">
               <graphic file="1029-242X-2010-960672-i6.gif"/>
            </display-formula>
         </p>
         <p>for all <inline-formula><graphic file="1029-242X-2010-960672-i7.gif"/></inline-formula>.</p>
         <p>Many generalizations, extensions and variations of this inequality have appeared in the literature; see [<abbr bid="B1">1</abbr>&#8211;<abbr bid="B10">10</abbr>] and the references given therein. In particular, in 2009, Wang and Zhao [<abbr bid="B11">11</abbr>] established a new Ostrowski-type inequality for higher-order derivatives as follows (see [<abbr bid="B11">11</abbr>] for definitions and notations): </p>
         <p/>
         <p>
            <display-formula id="M12">
               <graphic file="1029-242X-2010-960672-i8.gif"/>
            </display-formula>
         </p>
         <p/>
         <p>The main purpose of the present paper is to establish the following Ostrowski-type inequality involving higher-order partial derivatives (see next section for definitions and notations): </p>
         <p/>
         <p>
            <display-formula id="M13">
               <graphic file="1029-242X-2010-960672-i9.gif"/>
            </display-formula>
         </p>
         <p>where <inline-formula><graphic file="1029-242X-2010-960672-i10.gif"/></inline-formula> is a constant, <inline-formula><graphic file="1029-242X-2010-960672-i11.gif"/></inline-formula>, <inline-formula><graphic file="1029-242X-2010-960672-i12.gif"/></inline-formula> and <inline-formula><graphic file="1029-242X-2010-960672-i13.gif"/></inline-formula></p>
         <p>This is a generalization of inequality (1.2). </p>
         <p>Moreover, as applications, we get some interrelated results. Our results provide new estimates on such type of inequalities.</p>
      </sec>
      <sec>
         <st>
            <p>2. Main Results</p>
         </st>
         <p>Theorem 2.1. </p>
         <p>Suppose that</p>
         <p indent="1">(1)<inline-formula><graphic file="1029-242X-2010-960672-i14.gif"/></inline-formula> is continuous on <inline-formula><graphic file="1029-242X-2010-960672-i15.gif"/></inline-formula></p>
         <p indent="1">(2)<inline-formula><graphic file="1029-242X-2010-960672-i16.gif"/></inline-formula> is differentiable in <inline-formula><graphic file="1029-242X-2010-960672-i17.gif"/></inline-formula> up to order <inline-formula><graphic file="1029-242X-2010-960672-i18.gif"/></inline-formula>, with bounded <inline-formula><graphic file="1029-242X-2010-960672-i19.gif"/></inline-formula>th-order mixed partial derivatives <inline-formula><graphic file="1029-242X-2010-960672-i20.gif"/></inline-formula> (<inline-formula><graphic file="1029-242X-2010-960672-i21.gif"/></inline-formula> are natural numbers, and <inline-formula><graphic file="1029-242X-2010-960672-i22.gif"/></inline-formula>), that is, </p>
         <p>
            <display-formula id="M21">
               <graphic file="1029-242X-2010-960672-i23.gif"/>
            </display-formula>
         </p>
         <p/>
         <p indent="1">(3)there exists <inline-formula><graphic file="1029-242X-2010-960672-i24.gif"/></inline-formula> such that <inline-formula><graphic file="1029-242X-2010-960672-i25.gif"/></inline-formula>, <inline-formula><graphic file="1029-242X-2010-960672-i26.gif"/></inline-formula>; <inline-formula><graphic file="1029-242X-2010-960672-i27.gif"/></inline-formula></p>
         <p>then for any <inline-formula><graphic file="1029-242X-2010-960672-i28.gif"/></inline-formula>, </p>
         <p>
            <display-formula id="M22">
               <graphic file="1029-242X-2010-960672-i29.gif"/>
            </display-formula>
         </p>
         <p>where <inline-formula><graphic file="1029-242X-2010-960672-i30.gif"/></inline-formula></p>
         <p>Proof. </p>
         <p>From the hypotheses and using the <inline-formula><graphic file="1029-242X-2010-960672-i31.gif"/></inline-formula>-dimensional Taylor expansion of <inline-formula><graphic file="1029-242X-2010-960672-i32.gif"/></inline-formula> at <inline-formula><graphic file="1029-242X-2010-960672-i33.gif"/></inline-formula> we have, for some <inline-formula><graphic file="1029-242X-2010-960672-i34.gif"/></inline-formula></p>
         <p>
            <display-formula id="M23">
               <graphic file="1029-242X-2010-960672-i35.gif"/>
            </display-formula>
         </p>
         <p>Dividing both sides of (2.3) by <inline-formula><graphic file="1029-242X-2010-960672-i36.gif"/></inline-formula>, then integrating over <inline-formula><graphic file="1029-242X-2010-960672-i37.gif"/></inline-formula> from <inline-formula><graphic file="1029-242X-2010-960672-i38.gif"/></inline-formula> to <inline-formula><graphic file="1029-242X-2010-960672-i39.gif"/></inline-formula> first, and then integrating the resulting inequality over <inline-formula><graphic file="1029-242X-2010-960672-i40.gif"/></inline-formula> from <inline-formula><graphic file="1029-242X-2010-960672-i41.gif"/></inline-formula> to <inline-formula><graphic file="1029-242X-2010-960672-i42.gif"/></inline-formula>, we observe that </p>
         <p>
            <display-formula id="M24">
               <graphic file="1029-242X-2010-960672-i43.gif"/>
            </display-formula>
         </p>
         <p>Note that we have replaced the dummy variables <inline-formula><graphic file="1029-242X-2010-960672-i44.gif"/></inline-formula> by <inline-formula><graphic file="1029-242X-2010-960672-i45.gif"/></inline-formula>, respectively. From (2.3) and (2.4), we have </p>
         <p>
            <display-formula id="M25">
               <graphic file="1029-242X-2010-960672-i46.gif"/>
            </display-formula>
         </p>
         <p>Hence </p>
         <p>
            <display-formula id="M26">
               <graphic file="1029-242X-2010-960672-i47.gif"/>
            </display-formula>
         </p>
         <p>On the other hand, by applying the following two elementary inequalities [<abbr bid="B11">11</abbr>]: </p>
         <p>
            <display-formula id="M27">
               <graphic file="1029-242X-2010-960672-i48.gif"/>
            </display-formula>
         </p>
         <p>to the right-hand side of (2.6), we obtain </p>
         <p>
            <display-formula id="M28">
               <graphic file="1029-242X-2010-960672-i49.gif"/>
            </display-formula>
         </p>
         <p>This completes the proof.</p>
         <p>Remark. </p>
         <p>With suitable modifications, it is easy to see that (2.2) reduces to the following inequality in the 1-dimensional situation: </p>
         <p>
            <display-formula id="M29">
               <graphic file="1029-242X-2010-960672-i50.gif"/>
            </display-formula>
         </p>
         <p>where <inline-formula><graphic file="1029-242X-2010-960672-i51.gif"/></inline-formula> is continuous on <inline-formula><graphic file="1029-242X-2010-960672-i52.gif"/></inline-formula>, with <inline-formula><graphic file="1029-242X-2010-960672-i53.gif"/></inline-formula>th-order derivative <inline-formula><graphic file="1029-242X-2010-960672-i54.gif"/></inline-formula> bounded on <inline-formula><graphic file="1029-242X-2010-960672-i55.gif"/></inline-formula>, that is, <inline-formula><graphic file="1029-242X-2010-960672-i56.gif"/></inline-formula>, and <inline-formula><graphic file="1029-242X-2010-960672-i57.gif"/></inline-formula></p>
         <p>Observe that this is a recent result of Wang and Zhao [<abbr bid="B11">11</abbr>].</p>
         <p>Theorem. </p>
         <p>Suppose that</p>
         <p indent="1">(1)<inline-formula><graphic file="1029-242X-2010-960672-i58.gif"/></inline-formula> is continuous on <inline-formula><graphic file="1029-242X-2010-960672-i59.gif"/></inline-formula></p>
         <p indent="1">(2)<inline-formula><graphic file="1029-242X-2010-960672-i60.gif"/></inline-formula> is twice differentiable in <inline-formula><graphic file="1029-242X-2010-960672-i61.gif"/></inline-formula> with bounded second-order partial derivatives <inline-formula><graphic file="1029-242X-2010-960672-i62.gif"/></inline-formula> that is, </p>
         <p>
            <display-formula id="M210">
               <graphic file="1029-242X-2010-960672-i63.gif"/>
            </display-formula>
         </p>
         <p/>
         <p indent="1">(3)there exists <inline-formula><graphic file="1029-242X-2010-960672-i64.gif"/></inline-formula> such that <inline-formula><graphic file="1029-242X-2010-960672-i65.gif"/></inline-formula></p>
         <p>Then, one has </p>
         <p>
            <display-formula id="M211">
               <graphic file="1029-242X-2010-960672-i66.gif"/>
            </display-formula>
         </p>
         <p/>
         <p>Proof. </p>
         <p>From the hypotheses and in view of the <inline-formula><graphic file="1029-242X-2010-960672-i67.gif"/></inline-formula>-dimensional Taylor expansion, it easily follows that for some <inline-formula><graphic file="1029-242X-2010-960672-i68.gif"/></inline-formula>, </p>
         <p>
            <display-formula id="M212">
               <graphic file="1029-242X-2010-960672-i69.gif"/>
            </display-formula>
         </p>
         <p>Hence, </p>
         <p>
            <display-formula id="M213">
               <graphic file="1029-242X-2010-960672-i70.gif"/>
            </display-formula>
         </p>
         <p>This proves Theorem 2.3.</p>
         <p>Let <inline-formula><graphic file="1029-242X-2010-960672-i71.gif"/></inline-formula> and <inline-formula><graphic file="1029-242X-2010-960672-i72.gif"/></inline-formula> change to <inline-formula><graphic file="1029-242X-2010-960672-i73.gif"/></inline-formula> and <inline-formula><graphic file="1029-242X-2010-960672-i74.gif"/></inline-formula>, respectively, and with suitable modifications, Theorem 2.3 reduces to the following.</p>
         <p>Theorem. </p>
         <p>Suppose that</p>
         <p indent="1">(1)<inline-formula><graphic file="1029-242X-2010-960672-i75.gif"/></inline-formula> is continuous on <inline-formula><graphic file="1029-242X-2010-960672-i76.gif"/></inline-formula></p>
         <p indent="1">(2)<inline-formula><graphic file="1029-242X-2010-960672-i77.gif"/></inline-formula> is twice differentiable in <inline-formula><graphic file="1029-242X-2010-960672-i78.gif"/></inline-formula> with bounded second -order derivative, that is, <inline-formula><graphic file="1029-242X-2010-960672-i79.gif"/></inline-formula></p>
         <p indent="1">(3)there exists <inline-formula><graphic file="1029-242X-2010-960672-i80.gif"/></inline-formula> such that <inline-formula><graphic file="1029-242X-2010-960672-i81.gif"/></inline-formula> (or <inline-formula><graphic file="1029-242X-2010-960672-i82.gif"/></inline-formula>),</p>
         <p>then, one has </p>
         <p>
            <display-formula id="M214">
               <graphic file="1029-242X-2010-960672-i83.gif"/>
            </display-formula>
         </p>
         <p/>
         <p>This is another recent result of Wang and Zhao in [<abbr bid="B11">11</abbr>].</p>
      </sec>
   </bdy>
   <bm>
      <ack>
         <sec>
            <st>
               <p>Acknowledgments</p>
            </st>
            <p>The research is supported by the National Natural Sciences Foundation of China (10971205). It is partially supported by the Research Grants Council of the Hong Kong SAR, China (Project no. HKU7016/07P) and an HKU Seed Grant for Basic Research.</p>
         </sec>
      </ack>
      <refgrp><bibl id="B1"><aug><au><snm>Mtrinovi&#263;</snm><fnm>DS</fnm></au><au><snm>Pe&#269;ari&#263;</snm><fnm>JE</fnm></au><au><snm>Fink</snm><fnm>AM</fnm></au></aug><source>Inequalities for Functions and Their Integrals and Dervatives</source><publisher>Kluwer Academic Publishers, Dordrecht, The Netherlands</publisher><pubdate>1994</pubdate></bibl><bibl id="B2"><title><p>On an inequality of Ostrowski type in three independent variables</p></title><aug><au><snm>Pachpatte</snm><fnm>BG</fnm></au></aug><source>Journal of Mathematical Analysis and Applications</source><pubdate>2000</pubdate><volume>249</volume><issue>2</issue><fpage>583</fpage><lpage>591</lpage><xrefbib><pubid idtype="doi">10.1006/jmaa.2000.6913</pubid></xrefbib></bibl><bibl id="B3"><title><p>On a new Ostrowski type inequality in two independent variables</p></title><aug><au><snm>Pachpatte</snm><fnm>BG</fnm></au></aug><source>Tamkang Journal of Mathematics</source><pubdate>2001</pubdate><volume>32</volume><issue>1</issue><fpage>45</fpage><lpage>49</lpage></bibl><bibl id="B4"><title><p>Multivariate Ostrowski type inequalities</p></title><aug><au><snm>Anastassiou</snm><fnm>GA</fnm></au></aug><source>Acta Mathematica Hungarica</source><pubdate>1997</pubdate><volume>76</volume><issue>4</issue><fpage>267</fpage><lpage>278</lpage><xrefbib><pubid idtype="doi">10.1023/A:1006529405430</pubid></xrefbib></bibl><bibl id="B5"><title><p>A new inequality of Ostrowski's type in <inline-formula><graphic file="1029-242X-2010-960672-i84.gif"/></inline-formula> norm and applications to some special means and to some numerical quadrature rules</p></title><aug><au><snm>Dragomir</snm><fnm>SS</fnm></au><au><snm>Wang</snm><fnm>S</fnm></au></aug><source>Tamkang Journal of Mathematics</source><pubdate>1997</pubdate><volume>28</volume><issue>3</issue><fpage>239</fpage><lpage>244</lpage></bibl><bibl id="B6"><title><p>An inequality of Ostrowski-Gr&#252;ss' type and its applications to the estimation of error bounds for some special means and for some numerical quadrature rules</p></title><aug><au><snm>Dragomir</snm><fnm>SS</fnm></au><au><snm>Wang</snm><fnm>S</fnm></au></aug><source>Computers &amp; Mathematics with Applications</source><pubdate>1997</pubdate><volume>33</volume><issue>11</issue><fpage>15</fpage><lpage>20</lpage><xrefbib><pubidlist><pubid idtype="doi">10.1016/S0898-1221(97)00084-9</pubid><pubid idtype="pmpid" link="fulltext">22031654</pubid></pubidlist></xrefbib></bibl><bibl id="B7"><title><p>Applications of Ostrowski's inequality to the estimation of error bounds for some special means and for some numerical quadrature rules</p></title><aug><au><snm>Dragomir</snm><fnm>SS</fnm></au><au><snm>Wang</snm><fnm>S</fnm></au></aug><source>Applied Mathematics Letters</source><pubdate>1998</pubdate><volume>11</volume><issue>1</issue><fpage>105</fpage><lpage>109</lpage><xrefbib><pubid idtype="doi">10.1016/S0893-9659(97)00142-0</pubid></xrefbib></bibl><bibl id="B8"><title><p>An Ostrowski type inequality for double integrals and applications for cubature formulae</p></title><aug><au><snm>Barnett</snm><fnm>NS</fnm></au><au><snm>Dragomir</snm><fnm>SS</fnm></au></aug><source>RGMIA Research Report Collection</source><pubdate>1998</pubdate><volume>1</volume><fpage>13</fpage><lpage>23</lpage></bibl><bibl id="B9"><aug><au><snm>Ba&#301;nov</snm><fnm>D</fnm></au><au><snm>Simeonov</snm><fnm>P</fnm></au></aug><source>Integral Inequalities and Applications, Mathematics and Its Applications</source><publisher>Kluwer Academic Publishers, Dordrecht, The Netherlands</publisher><pubdate>1992</pubdate><volume>57</volume><fpage>xii+245</fpage></bibl><bibl id="B10"><aug><au><snm>Mitrinovi&#263;</snm><fnm>DS</fnm></au><au><snm>Pe&#269;ari&#263;</snm><fnm>JE</fnm></au><au><snm>Fink</snm><fnm>AM</fnm></au></aug><source>Inequalities Involving Functions and Their Integrals and Derivatives, Mathematics and Its Applications</source><publisher>Kluwer Academic Publishers, Dordrecht, The Netherlands</publisher><pubdate>1991</pubdate><volume>53</volume><fpage>xvi+587</fpage></bibl><bibl id="B11"><title><p>Ostrowski type inequalities for higher-order derivatives</p></title><aug><au><snm>Wang</snm><fnm>M</fnm></au><au><snm>Zhao</snm><fnm>X</fnm></au></aug><source>Journal of Inequalities and Applications</source><pubdate>2009</pubdate><volume>2009</volume><lpage>8</lpage></bibl></refgrp>
   </bm>
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