 鲜花( 19)  鸡蛋( 0)
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Originally posted by gnome-kde at 2005-4-6 20:30:8 f E) m+ h$ H2 n( N- f
这样算混淆了微分和导数的概念。
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2 p: q0 A2 }" e {& l2 C" 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" A& T3 ` U3 @4 y8 U* P
3 t8 F! M" |8 m# ~) O% @If h(x)=(a+bx)*C(x)/x, then d(h(x))/dx = d{(a+bx)*C(x)/x}/dx = h ... " Q" ~* U9 P3 G3 f. S; L1 h
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这样算混淆了微分和导数的概念。
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0 M- T) y6 M9 o5 ^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4 T/ X0 ~* h- _* M0 @' X& M! a
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Ah, you made a mistake: it should be:/ `$ b1 f* s5 T I
6 x# `2 g, q. w+ }1 |/ k" V( }d(f(x)g(x))/dx = f(x) d(g(x))/dx + g(x) d(f(x))/dx 3 F: R! E* J$ w+ a2 Q
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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): q& N* \1 A! M0 _
8 s# f* v5 n$ j, o( ?8 ^4 ?for h(x)=(a+bx)*C(x)/x, you are right, But, no x there, it is:
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h(x)=(a+bx)*C(x) |
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