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We constantly work with functions at university, but this one is baffling me. It's a simple one - yet I can't get my head around it and I get stuck after taking out f''(x) (second derivative).

Could someone walk me through it? Thanks in advance! $ \frac{(x^2+x+1)}{(x^2-1)} $

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    Hm, what have you tried to do? What did you get stuck at? We need these pieces of information to write such amazing answers to you sadly. – 2017-01-11
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    I got stuck at 2nd derivative (ergo, f''(x)) - and precisely at the point where I've put it into trinomial. – 2017-01-11
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    Well, then you should at least include what $f'(x)$ is, how you got it, what you tried to do to get $f''(x)$, etc. – 2017-01-11

1 Answers 1

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hint

Your function can be written as

$$f(x)=1+\frac{x+2}{x^2-1}$$ $$=1+\frac{1}{x-1}+\frac{1}{x^2-1}$$

$$=1+\frac{3}{2(x-1)}-\frac{1}{2(x+1)}$$

You can take it from here.

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    The fact that the denominator was factor-able should've made this obvious. :D – 2017-01-11