推 CRAZYAWIND:真強....... 12/10 01:48
※ 編輯: birdhackor 來自: 140.116.91.47 (12/10 12:11)
: yp3=----- -----------------
: D-4 (e^2t+1)^3/2
: e^-t
: =e^4t∫------------dt
: (e^2t+1)^3/2
: 1
: =x^4∫--------------dx
: x^2(x^2+1)^3/2
1
∫--------------dx 令x=tan(p)
x^2(x^2+1)^3/2
1
=∫-------------------sec^2(p)dp
tan^2(p)*sec^3(p)
cos^3(p)
=∫----------dp
sin^2(p)
cos^2(p)
=∫----------d[sin(p)]
sin^2(p)
1-sin^2(p)
=∫------------d[sin(p)]
sin^2(p)
1
=∫----------d[sin(p)] -∫ 1 d[sin(p)]
sin^2(p)
= -[sin(p)]^(-1) - sin(p)
-x -(1+x^2)^(1/2)
= ------------- + ----------------
(1+x^2)^(1/2) x
-(1+2x^2)
= -----------------
x*(1+x^2)^(1/2)
不用IBP的方式
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 118.171.117.191