Precalculus Examples

$f (x, y) = \sqrt{x - y}$

Step 1

Set the radicand in $\sqrt{x - y}$ greater than or equal to $0$ to find where the expression is defined.

$x - y \geq 0$

Step 2

Add $y$ to both sides of the inequality.

$x \geq y$

Step 3

The domain is all real numbers.

Interval Notation:

$(- \infty, \infty)$

Set-Builder Notation:

${x | x \in ℝ}$