f(x)=x/x^2+1(adsbygoogle = window.adsbygoogle || []).push({});

f'(x)= 1-x^2/(x^2+1)^2

But then I can't seem to work through taking the 2nd derivative, perhaps I am not using the chain rule right.

I get -4x^5-2x^3-2x/(x^2+1)^4

But thats not right... please help!

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# 2nd derivative trouble

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