Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.)

Question

Square root of (x^2 -9

Need answer in interval notation. thanks!

Answer 1

For the expression to be a real number, x² - 9 must be greater than or equal to zero.

x² - 9 ≥ 0

x² ≥ 9

x ≥ 3 or x ≤ -3

Using interval notations:

x = [-∞, -3] U [3,∞]