作者walolo (有缘无份)
看板trans_math
标题Re: [积分] 几题积分
时间Tue Mar 6 15:41:00 2007
※ 引述《LuisSantos (^______^)》之铭言：
: ※ 引述《walolo (有缘无份)》之铭言：
: : 3.∫θ√1-cosθ dθ
: ∫(θ)(√(1 - cosθ)) dθ
: = ∫(θ)(√(1 - (1 - (2)((sin(θ/2))^2)))) dθ
: = ∫(θ)(√((2)((sin(θ/2))^2))) dθ
: = ∫(θ)(√2)(sin(θ/2)) dθ
: = (√2)(∫(θ)(sin(θ/2)) dθ)
这一行怎麽转到下一行的...有点看不太懂@.@
: = (√2)((-2)(θ)(cos(θ/2)) - ∫(-2)(cos(θ/2)) dθ)
: = (√2)((-2)(θ)(cos(θ/2)) - (-4)(sin(θ/2))) + c
: = (√2)((-2θ)(cos(θ/2)) + (4)(sin(θ/2))) + c
: = (-2)(√2)(θ)(cos(θ/2)) + (4√2)(sin(θ/2)) + c
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1F：推 doa2:分部积分 219.84.128.123 03/06 15:48