Question

What are the excluded values of x for $\frac{x+1}{x^2-1}$

A. x = –1, x = 0, x = 1
B. x = –1, x = 0
C. x = 0, x = 1
D. x = –1, x = 1

Answer 1

Denominator:

$x^2-1=(x+1)(x-1)=\big(x-(-1)\big)(x-1)$

so excluded values are x =  -1 and x = 1.

Answer D.

Answer 2

The answer would be D. x=-1, x=1