作者LuisSantos (^______^)
看板trans_math
標題Re: [微分] 92政大財管
時間Sun Jan 6 17:21:27 2008
※ 引述《bitchdog (PEaCE)》之銘言:
: y^4+(x^2)(y^2)+x^4=1 dy =?
: ----
: dx
等號兩邊對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)
--
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