 鲜花( 19)  鸡蛋( 0)
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Originally posted by gnome-kde at 2005-4-6 20:30:
! |7 _! }: U2 Y, Z' z, t这样算混淆了微分和导数的概念。
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& W3 d. y# P% D) a! od(f(x))/dx = f'(x), d(f(x)g(x))/dx = f'(x) d(g(x))/dx + g'(x) d(f(x))/dx 这是基本的微分四则运算5 d: o7 T- [5 J) g- C, y4 U% @2 t
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If h(x)=(a+bx)*C(x)/x, then d(h(x))/dx = d{(a+bx)*C(x)/x}/dx = h ...
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$ ^& T- K9 W/ E) l w. w这样算混淆了微分和导数的概念。
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$ e* V( f. \# G$ m! g z- C1 D: I+ Md(f(x))/dx = f'(x), d(f(x)g(x))/dx = f'(x) d(g(x))/dx + g'(x) d(f(x))/dx 这是基本的微分四则运算
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) {7 U- k" X6 z* WAh, you made a mistake: it should be:
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d(f(x)g(x))/dx = f(x) d(g(x))/dx + g(x) d(f(x))/dx
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4 h' X( N3 M& ]# Y& W# c \9 A7 MIf h(x)=(a+bx)*C(x)/x, then d(h(x))/dx = d{(a+bx)*C(x)/x}/dx = h'(x) = [xb*c(x)+x(a+bx)*c'(x)-(a+bx)*c(x)]/x2 (应该对吧, 我也没验算)9 s. p9 M, u2 w% N8 K$ }: B
( X0 h9 k2 e& S, \0 h1 z+ f7 N+ M9 ]for h(x)=(a+bx)*C(x)/x, you are right, But, no x there, it is:1 j; I; }% @% t
1 Q+ n9 w) h; Y. D' @5 ^h(x)=(a+bx)*C(x) |
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