作者LuisSantos ( )
看板trans_math
标题Re: [考古] 91政大国贸
时间Sun Jun 29 12:52:49 2008
※ 引述《applexgreen (亲爱的早安)》之铭言：
: 2.(C)
: 1 1
: lim ( ---------- － --------)
: x→0 sin^2x x^2
: 好像看过类似的题目但是脑筋就是卡住...
1 1
lim (------------ - -----)
x→0 (sin(x))^2 x^2
x^2 - (sin(x))^2
= lim (--------------------)
x→0 (x^2)((sin(x))^2)
x^2 - (sin(x))^2 x^2
= lim (------------------)(------------)
x→0 x^4 (sin(x))^2
x^2 - (sin(x))^2 x
= (lim ----------------)((lim --------)^2)
x→0 x^4 x→0 sin(x)
2x - sin(2x)
= (lim ------------)(1^2)
x→0 (4)(x^3)
2 - (2)(cos(2x))
= lim ------------------
x→0 (12)(x^2)
(4)(sin(2x))
= lim --------------
x→0 24x
1 sin(2x) 1 1
= (---)(lim ---------) = (---)(1) = ---
3 x→0 2x 3 3
: 3. Find constants a and b for which
: π
: F(a,b)=∫[sinx-(ax^2+bx)]^2 dx
: 0
: is a minimum
: http://www.lib.nccu.edu.tw/exam/transfer/it/it91.pdf 如果看不清楚题目可以看原档
: 先谢谢你:-)
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◆ From: 140.119.29.31
1F：推 applexgreen:)))))))))))118.160.149.146 06/29 14:17
2F：推 applexgreen:我之前会的就是这个方法! 谢了118.160.149.146 06/29 14:21
3F：推 applexgreen:把1/3提出来的那里好像怪怪的哦118.160.149.146 06/29 14:38
4F：→ Honor1984:4/12 = 1/3 没错122.124.103.126 06/29 17:48
5F：→ applexgreen:喔 原来是又罗毕达一次 谢谢118.168.161.248 06/29 19:07