{"id":2173,"date":"2012-04-16T15:00:33","date_gmt":"2012-04-16T07:00:33","guid":{"rendered":"http:\/\/wamath.sinaapp.com\/?p=2173"},"modified":"2012-04-16T15:00:33","modified_gmt":"2012-04-16T07:00:33","slug":"2009%e4%b8%ad%e7%a7%91%e5%a4%a7%e6%95%b0%e5%ad%a6%e5%88%86%e6%9e%90","status":"publish","type":"post","link":"https:\/\/lttt.vanabel.cn\/?p=2173","title":{"rendered":"2009\u4e2d\u79d1\u5927\u6570\u5b66\u5206\u6790"},"content":{"rendered":"<p>\\begin{enumerate}<br \/>\n\\item \u5224\u65ad<br \/>\n\\begin{enumerate}<br \/>\n\\item \\[\\sum_{n=0}^{+\\infty}\\frac{(1+2i)^n}{3^n-2^n}\\]\u7684\u6536\u655b\u6027.<br \/>\n\\item $f$ \u4e00\u81f4\u6536\u655b\u7684\u5145\u8981\u6761\u4ef6\u662f $f$ \u628a Cauchy \u5217\u6620\u6210 Cauchy \u5217.<br \/>\n\\end{enumerate}<br \/>\n<!--more--><br \/>\n\\item \u586b\u7a7a<br \/>\n\\begin{enumerate}<br \/>\n\\item $f(x)=1-x$ \u5728 $x=-1$ \u5904\u5c55\u5f00\u540e\u7ea7\u6570\u7684\u6536\u655b\u70b9\u96c6\u662f________;<br \/>\n\\item $\\sin(x^2)=x$ \u6709________\u4e2a\u6839;<br \/>\n\\item \u6c42<br \/>\n\\[<br \/>\n\\sum_{k=1}^{+\\infty}\\left(\\frac{1}{2k-1}-\\frac{1}{4k-2}-\\frac{1}{4k}\\right)<br \/>\n\\]<br \/>\n\u7684\u548c________.<br \/>\n\\end{enumerate}<br \/>\n\\item $f:[0,1]\\to\\R$ \u5355\u8c03\u9012\u589e\u4e14 $f([0,1])$ \u662f\u95ed\u96c6, \u8bc1\u660e $f$ \u5728 $[0,1]$ \u4e0a\u8fde\u7eed.<br \/>\n\\item $f$ \u5728 $[0,1]$ \u4e0a\u8fde\u7eed, \u4e14<br \/>\n\\[<br \/>\n\\int_0^1 f(x)x^n\\rd x=0,\\quad n=0,1,2,\\ldots,<br \/>\n\\]<br \/>\n\u8bc1\u660e $f\\equiv0$.<br \/>\n\\item \u662f\u5426\u5b58\u5728\u539f\u51fd\u6570 $F$, \u4f7f\u5f97 $\\rd F$ \u6ee1\u8db3<br \/>\n\\[<br \/>\n\\rd F=\\frac{x\\rd y-y\\rd x}{\\sqrt{x^2+y^2}}.<br \/>\n\\]<br \/>\n\\item \u8bbe $f:N\\to N$ \u4e14 $f^{-1}(N)$ \u662f\u6709\u9650\u96c6. \u82e5 $\\lim\\limits_{n\\to+\\infty}x_n$ \u5b58\u5728, \u5219 $\\lim\\limits_{n\\to+\\infty}x_{f(n)}$ \u4e5f\u5b58\u5728.<br \/>\n\\item \u4ee4 $S=\\set{(x,y,z)\\in\\R^3|xy^2z^3=1}$<br \/>\n\\begin{enumerate}<br \/>\n\\item \u8bc1\u660e $S$ \u5728 $\\R^3$ \u4e0a\u786e\u5b9a\u4e00\u5f20\u9690\u5f0f\u66f2\u9762, \u5e76\u6c42\u51fa\u4e00\u4e2a\u5728\u70b9 $(1,1,1)$ \u9644\u8fd1\u7684\u53c2\u6570\u65b9\u7a0b;<br \/>\n\\item $S$ \u662f\u5426\u8fde\u901a? \u662f\u5426\u7d27\u81f4?<br \/>\n\\item \u5bf9\u70b9 $q\\in S$, \u4ee5 $|q|$ \u8868\u793a\u5176\u5230\u539f\u70b9\u7684\u8ddd\u79bb. \u8bd5\u6c42\u6240\u6709\u6ee1\u8db3<br \/>\n\\[<br \/>\n|p|=\\inf_{q\\in S}|q|<br \/>\n\\]<br \/>\n\u7684 $p$ \u6240\u6210\u4e4b\u96c6.<br \/>\n\\end{enumerate}<br \/>\n\\item \u8bc1\u660e\u6052\u7b49\u5f0f<br \/>\n\\[<br \/>\n\\pi\\sum_{n=-\\infty}^{+\\infty}e^{2\\pi|n|}=\\sum_{n=-\\infty}^{+\\infty}\\frac{1}{n^2+1}.<br \/>\n\\]<br \/>\n\\item \u4ee4 $\\Gamma(s)=\\int_0^\\infty x^{s-1}e^{-x}\\rd x$, $S=\\set{(x,y,z)\\in\\R^3|x^2+y^2+z^2=1}$. \u8bd5\u7528 $\\Gamma(s)$ \u8868\u793a\u7b2c\u4e00\u578b\u79ef\u5206<br \/>\n\\[<br \/>\n\\int_S (x^2+y^2)^a\\rd\\sigma,<br \/>\n\\]<br \/>\n\u5176\u4e2d $a>-1$.<br \/>\n\\end{enumerate}<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\\begin{enumerate} \\item \u5224\u65ad \\begin{enumer &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"more-link\" href=\"https:\/\/lttt.vanabel.cn\/?p=2173\"> <span class=\"screen-reader-text\">2009\u4e2d\u79d1\u5927\u6570\u5b66\u5206\u6790<\/span> \u9605\u8bfb\u66f4\u591a &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[659,804,332],"class_list":["post-2173","post","type-post","status-publish","format-standard","hentry","category-mathnotes","tag-ustc","tag-804","tag-332"],"_links":{"self":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts\/2173","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2173"}],"version-history":[{"count":0,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts\/2173\/revisions"}],"wp:attachment":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2173"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2173"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}