# Math Help - domain of function

1. ## domain of function

Im not quite sure how to find the domain on the function f(x)=the square root of x squared-4

2. Originally Posted by bastropgarl
Im not quite sure how to find the domain on the function f(x)=the square root of x squared-4
$f(x) \geq 0$ therefore $\sqrt{x^2-4} = \sqrt{(x-2)(x+2)} \geq 0$

Solve for x.

3. Originally Posted by bastropgarl
Im not quite sure how to find the domain on the function f(x)=the square root of x squared-4
Hi bastropgarl,

$f(x)=\sqrt{x^2-4}$

The domain is all values of x such that $x^2-4 \ge 0$

This graph has x-intercepts are -2 and +2.

The domain will be the values to the left of -2 and to the right of +2. The values between -2 and +2 are not part of the domain. For instance, zero is not in the domain.

Domain = $\{x|x \ge 2 \ \ or \ \ x \le -2\}$