f(x) = g(x)是对的,因为它们都是导数
证明:
∫ f(x) dx = ∫ g(x) dx
d/dx ∫ f(x) dx = d/dx ∫ g(x) dx
=> f(x) = g(x)
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未必相等的是它们的原函数
∫ f(x) dx = ∫ g(x) dx
F(x) + C1 = G(x) + C2,F(x)是f(x)的原函数,G(x)是g(x)的原函数
∵C1≠C2
∴F(x)≠G(x)
即F(x) = G(x) + C3,C1≠C2≠C3
追问那解释下∫f(x)dx=f(x)+c,则f(x)=e^x为什么错了?
追答∫ f(x) dx = f(x) + C1
d/dx ∫ f(x) dx = d/dx f(x) + d/dx C1
f(x) = f'(x)
f'(x)/f(x) = 1
[lnf(x)]' = 1,复合函数求导公式[lnf(x)]' = [1/f(x)] * f'(x)
lnf(x) = x + C2
f(x) = e^(x + C2)
= (e^x)(e^C2)
= C3*e^x
C1≠C2≠C3