How do you find the domain of $(x+1)/(x^2 - 1)$ ?

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Answer 1 · 2017-04-29T09:24:43

The domain of $RR-{-1,1}$

We need

$a^2-b^2=(a+b)(a-b)$

Let rewrite the function by factorising

$(x+2)/(x^2-1)=(x+2)/((x+1)(x-1))$

Let $f(x)=(x+2)/((x+1)(x-1))$

As we cannot divide by $0$ , $x!=1$ and $x!=-1$

Therefore,

the domain of $f(x)$ is $D_f(x)=RR-{-1,1}$

How do you find the domain of (x+1)/(x^2 - 1)(x+1)/(x^2 - 1)?