作者r19891011 (弧形)
看板trans_math
标题Re: [积分]
时间Wed Nov 4 21:38:34 2009
※ 引述《midarmyman (midarmyman)》之铭言:
: f(x) decrease and nonnegative
: k+1
: ∫ f(x)dx=f(k)?
: k
: 为啥会等於f(k)?
先举一例 f(x)=e^(-x)
k+1 k+1
∫ f(x)dx=-e^(-x) | =f(k)-f(k+1)
k k
我猜你想说的应该是
k+1
∫ f(x)dx=f(x'), k < x'< k+1 (积分均值定理)
k
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◆ From: 122.124.98.116
1F:推 midarmyman:为啥我打的那边他没-f(k+1) 140.117.198.78 11/04 21:57
2F:→ midarmyman:原题有改 见原文 140.117.198.78 11/04 22:03