Precalculus Examples

$\frac{4 a}{a + b}$

Step 1

Set the denominator in $\frac{4 a}{a + b}$ equal to $0$ to find where the expression is undefined.

$a + b = 0$

Step 2

Subtract $b$ from both sides of the equation.

$a = - b$

Step 3

The domain is all real numbers.

Interval Notation:

$(- \infty, \infty)$

Set-Builder Notation:

${a | a \in ℝ}$