鞋匠刀问题
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=4205&fromuid=9502
(出处: 数学研发论坛)
找数：<span class="MathJax_Preview" style="color: inherit; display: none;"></span><span class="MathJax" id="MathJax-Element-3-Frame" tabindex="0" data-mathml="<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>n</mi><mo>=</mo><msup><mi>a</mi><mi>r</mi></msup><mo>+</mo><msup><mi>b</mi><mi>r</mi></msup><mo>=</mo><msup><mi>c</mi><mi>r</mi></msup><mo>+</mo><msup><mi>d</mi><mi>r</mi></msup></math>" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-22" style="width: 12.214em; display: inline-block;"><span style="display: inline-block; position: relative; width: 9.377em; height: 0px; font-size: 130%;"><span style="position: absolute; clip: rect(1.541em 1009.38em 2.599em -999.998em); top: -2.353em; left: 0em;"><span class="mrow" id="MathJax-Span-23"><span class="mi" id="MathJax-Span-24" style="font-family: MathJax_Math-italic;">n</span><span class="mo" id="MathJax-Span-25" style="font-family: MathJax_Main; padding-left: 0.291em;">=</span><span class="msubsup" id="MathJax-Span-26" style="padding-left: 0.291em;"><span style="display: inline-block; position: relative; width: 0.916em; height: 0px;"><span style="position: absolute; clip: rect(3.416em 1000.53em 4.137em -999.998em); top: -3.988em; left: 0em;"><span class="mi" id="MathJax-Span-27" style="font-family: MathJax_Math-italic;">a</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span><span style="position: absolute; top: -4.373em; left: 0.531em;"><span class="mi" id="MathJax-Span-28" style="font-size: 70.7%; font-family: MathJax_Math-italic;">r</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span></span></span><span class="mo" id="MathJax-Span-29" style="font-family: MathJax_Main; padding-left: 0.243em;">+</span><span class="msubsup" id="MathJax-Span-30" style="padding-left: 0.243em;"><span style="display: inline-block; position: relative; width: 0.82em; height: 0px;"><span style="position: absolute; clip: rect(3.175em 1000.43em 4.137em -999.998em); top: -3.988em; left: 0em;"><span class="mi" id="MathJax-Span-31" style="font-family: MathJax_Math-italic;">b</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span><span style="position: absolute; top: -4.373em; left: 0.435em;"><span class="mi" id="MathJax-Span-32" style="font-size: 70.7%; font-family: MathJax_Math-italic;">r</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span></span></span><span class="mo" id="MathJax-Span-33" style="font-family: MathJax_Main; padding-left: 0.291em;">=</span><span class="msubsup" id="MathJax-Span-34" style="padding-left: 0.291em;"><span style="display: inline-block; position: relative; width: 0.82em; height: 0px;"><span style="position: absolute; clip: rect(3.416em 1000.43em 4.137em -999.998em); top: -3.988em; left: 0em;"><span class="mi" id="MathJax-Span-35" style="font-family: MathJax_Math-italic;">c</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span><span style="position: absolute; top: -4.373em; left: 0.435em;"><span class="mi" id="MathJax-Span-36" style="font-size: 70.7%; font-family: MathJax_Math-italic;">r</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span></span></span><span class="mo" id="MathJax-Span-37" style="font-family: MathJax_Main; padding-left: 0.243em;">+</span><span class="msubsup" id="MathJax-Span-38" style="padding-left: 0.243em;"><span style="display: inline-block; position: relative; width: 0.964em; height: 0px;"><span style="position: absolute; clip: rect(3.175em 1000.53em 4.137em -999.998em); top: -3.988em; left: 0em;"><span class="mi" id="MathJax-Span-39" style="font-family: MathJax_Math-italic;">d<span style="display: inline-block; overflow: hidden; height: 1px; width: 0.002em;"></span></span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span><span style="position: absolute; top: -4.373em; left: 0.579em;"><span class="mi" id="MathJax-Span-40" style="font-size: 70.7%; font-family: MathJax_Math-italic;">r</span><span style="display: inline-block; width: 0px; height: 3.993em;"></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.358em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.184em; border-left-width: 0px; border-left-style: solid; width: 0px; height: 1.128em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>n</mi><mo>=</mo><msup><mi>a</mi><mi>r</mi></msup><mo>+</mo><msup><mi>b</mi><mi>r</mi></msup><mo>=</mo><msup><mi>c</mi><mi>r</mi></msup><mo>+</mo><msup><mi>d</mi><mi>r</mi></msup></math></span></span><script type="math/tex" id="MathJax-Element-3">n = a^r + b^r = c^r + d^r</script>
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5351&fromuid=9502
(出处: 数学研发论坛)
求助满足1到7次方等幂和等积的两个正整数数组!
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5853&fromuid=9502
(出处: 数学研发论坛)
硬币投掷 想要出10次正面 平均需要投掷20次 这句话错了吗？
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5886&fromuid=9502
(出处: 数学研发论坛)
如下不定方程若有整数解，则A, B应满足什么条件
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5904&fromuid=9502
(出处: 数学研发论坛)
菲波那契数前n项的k次方求和，有公式么
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5902&fromuid=9502
(出处: 数学研发论坛)
一个三角恒等式问题
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5913&fromuid=9502
(出处: 数学研发论坛)
求解一组合计数问题
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5995&fromuid=9502
(出处: 数学研发论坛)
有界函数的第n阶导数也有界，如何估计其中第i阶导数的界
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=5932&fromuid=9502
(出处: 数学研发论坛)
一道组合题求助
http://bbs.emath.ac.cn/forum.php?mod=viewthread&tid=6020&fromuid=9502
(出处: 数学研发论坛)