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发帖数: 431 | 1 实在忘了怎么解了，大侠帮忙噢。/bow ~~ 题目是:
let f:R -> R be a differntiable function for all x属于R。 Prove that if
f（ab）=f(a)f(b) for all a,b属于R, Then f(x)的导数=f(x) for all x属于R.
Given an example of a function satisfying f(ab)=f(a)f(b) for all x属于R。 | p******s
发帖数: 15 | | y******i
发帖数: 69 | 3 should be if f(a+b)=f(a)f(b) then f'(x)=c f(x), where c=f'(0).
ex. f(x)=e^{cx} |
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