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}#