(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let f:R->R, differentiable, f(1)=1 and f'(1)=2.

2. Relevant equations

Prove that g:R->R such that g(x)=f(x)Arctg(f(x)) is differentiable in x=1 and calculate g'(1)

3. The attempt at a solution

I would prove it saying that if a function is differentiable then the product and composition it's differentiable, but I don't think is that simple, am I wrong?

Thanks!

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# Homework Help: Proof that a function composition is differentiable

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