 鲜花( 19)  鸡蛋( 0)
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Originally posted by gnome-kde at 2005-4-6 20:30:
4 ~% {. W0 s0 y这样算混淆了微分和导数的概念。
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! r. v1 @/ R+ _5 }0 W+ `* l |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 ... ! D+ t+ H! H+ u. E
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这样算混淆了微分和导数的概念。* y) X0 V% A- h( I f3 Z7 y
+ @& Y& w' A/ L+ a) M% Rd(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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& q3 A" f! g0 v0 mAh, you made a mistake: it should be: r; t/ g; G/ E4 j/ x: t! J
7 x$ Y4 I1 f' q: J. [% c( `d(f(x)g(x))/dx = f(x) d(g(x))/dx + g(x) d(f(x))/dx " ]5 R+ C. {9 A9 o! R$ h1 _
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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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7 S: h) z. N, F( lfor h(x)=(a+bx)*C(x)/x, you are right, But, no x there, it is:$ w! s8 p' p, [% w
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h(x)=(a+bx)*C(x) |
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