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

Aug 16, 2016

Domain$= \left\{x | x \epsilon \mathbb{R} , x \ne 1 , x \ne - 1\right\}$

#### Explanation:

Factorise the denominator first.

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

The denominator may not be zero. The two values of $x$ which will make the denominator are $x = 1 , \mathmr{and} x = - 1$

Domain$= \left\{x | x \epsilon \mathbb{R} , x \ne 1 , x \ne - 1\right\}$