作者LuisSantos (^______^)
看板trans_math
标题Re: [微分] 92政大财管
时间Sun Jan 6 17:21:27 2008
※ 引述《bitchdog (PEaCE)》之铭言：
: y^4+(x^2)(y^2)+x^4=1 dy =?
: ----
: dx
等号两边对x微分得
dy dy
(4)(y^3)(----) + (2x)(y^2) + (x^2)(2y)(----) + (4)(x^3) = 0
dx dx
dy
((4)(y^3) + (2)(x^2)(y))(----) = (-2)(x)(y^2) - (4)(x^3)
dx
dy (-2)(x)(y^2) - (4)(x^3)
---- = -------------------------
dx (4)(y^3) + (2)(x^2)(y)
(2)((-x)(y^2) - (2)(x^3))
= ---------------------------
(2)((2)(y^3) + (x^2)(y))
(-x)(y^2) - (2)(x^3)
= ----------------------
(2)(y^3) + (x^2)(y)
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.119.29.26