Precalculus Examples

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

Step 1

Set the denominator in $\frac{1}{x - 1}$ equal to $0$ to find where the expression is undefined.

$x - 1 = 0$

Step 2

Add $1$ to both sides of the equation.

$x = 1$

Step 3

Set the denominator in $\frac{1}{x + 1}$ equal to $0$ to find where the expression is undefined.

$x + 1 = 0$

Step 4

Subtract $1$ from both sides of the equation.

$x = - 1$

Step 5

The domain is all values of $x$ that make the expression defined.

Interval Notation:

$(- \infty, - 1) \cup (- 1, 1) \cup (1, \infty)$

Set-Builder Notation:

${x | x \neq 1, - 1}$

Step 6