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

Subtract $y$ from both sides of the inequality.

$x \geq - y$

Step 3

The domain is all real numbers.

Interval Notation:

$(- \infty, \infty)$

Set-Builder Notation:

${x | x \in ℝ}$