On Two Double Inequalities (Optimal Bounds and Sharps Bounds) for Centroidal Mean in Terms of Contraharmonic and Arithmetic Means

• 作者: Hamad Alharbi Mohammed El Mokhtar Ould El Mokhtar
• 来源期刊: 应用数学与应用物理(英文)
• 学科: 数学
• 关键词: Centroidal Mean Arithmetic Mean Contraharmonic Mean
• 年，卷（期）: 2020,（6）
• 页码范围: 1039-1046
• 页数: 8页
• 分类号: O17

摘要

This research work considers the following inequalities: <i>λ</i><em>A</em>(<i>a</i>,<i>b</i>) + (1-<i>λ</i>)<em>C</em>(<i>a</i>,<i>b</i>) ≤ <span style="text-decoration:overline;">C</span>(<i>a</i>,<i>b</i>) ≤ <i>μ</i><em>A</em>(<i>a</i>,<i>b</i>) + (1-<i>μ</i>)<em>C</em>(<i>a</i>,<i>b</i>) and <em>C</em>[<i>λ</i><em>a</em> + (1-<i>λ</i>)<em>b</em>, <i>λ</i><em>b</em> + (1-<i>λ</i>)<em>a</em>] ≤ <span style="text-decoration:overline;">C</span>(<i>a</i>,<i>b</i>) ≤ <em>C</em>[<i>μ</i><em>a</em> + (1-<i>μ</i>)<em>b</em>, <i>μ</i><em>b</em> + (1-<i>μ</i>)<em>a</em>] with <img src="Edit_ce892b1d-c056-44ea-a929-31dbcd1b0e91.bmp" alt="" /> . The researchers attempt to find an answer as to what are the best possible parameters <i>λ</i>, <i>μ</i> that (1.1) and (1.2) can be hold? The main tool is the optimization of some suitable functions that we seek to find out. By searching the best possible parameters such that (1.1) and (1.2) can be held. Firstly, we insert <em>f</em>(<i>t</i>) = <i>λ</i><em>A</em>(<i>a</i>,<i>b</i>) + (1-<i>λ</i>)<em>C</em>(<i>a</i>,<i>b</i>) - <span style="text-decoration:overline;">C</span>(<i>a</i>,<i>b</i>) without the loss of generality. We assume that <i>a</i>><i>b</i> and let <img src="Edit_efa43881-9a60-44f8-a86f-d4a1057f4378.bmp" alt="" /> to determine the condition for <i>λ</i> and <i>μ</i> to become f (<i>t</i>) ≤ 0. Secondly, we insert g(<i>t</i>) = <i>μ</i><em>A</em>(<i>a</i>,<i>b</i>) + (1-<i>μ</i>)<em>C</em>(<i>a</i>,<i>b</i>) - <span style="text-decoration:overline;">C</span>(<i>a</i>,<i>b</i>) without the loss of generality. We assume that <i>a</i>><i>b</i> and let <img src="Edit_750dddbb-1d71-45d3-be29-6da5c88ba85d.bmp" alt="" /> to determine the condition for <i>λ</i> and <i>μ</i> to become <em>g</em>(<i>t</i>) ≥ 0.