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Originally posted by gnome-kde at 2005-4-6 20:30:% P$ I* j6 |: J+ m
这样算混淆了微分和导数的概念。; Z! C) \5 q) S+ h' p s. p
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d(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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If h(x)=(a+bx)*C(x)/x, then d(h(x))/dx = d{(a+bx)*C(x)/x}/dx = h ... ( v/ T$ V8 j$ G6 X) Y
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这样算混淆了微分和导数的概念。5 d! E' L; J$ y$ m3 `
8 {* l: Z; z A& O9 z6 p$ {d(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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3 u7 i8 Z& z1 K, XAh, you made a mistake: it should be:4 i3 V- x& J' o+ F6 d( w9 r
3 V/ T F2 j1 k, G& dd(f(x)g(x))/dx = f(x) d(g(x))/dx + g(x) d(f(x))/dx
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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'(x) = [xb*c(x)+x(a+bx)*c'(x)-(a+bx)*c(x)]/x2 (应该对吧, 我也没验算)
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% b2 o6 e1 U$ Mfor h(x)=(a+bx)*C(x)/x, you are right, But, no x there, it is:
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- J5 f% z& E9 Z' O3 Vh(x)=(a+bx)*C(x) |
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