# How do you find the domain and range of #sqrt(x^2- 4)#?

##### 1 Answer

Dec 13, 2017

The domain:

the range:

#### Explanation:

The best and fastest way is to learn how do parental functions look like and how does the formula look like and then use it.

The domain: square root must be greater or equal to 0:

That happens only when f(x)>0......everything that is above x axis, like this:(i usually draw a simple picture of quadratic function)

There are many ways to find the range. I do it like this: parental square root starts in

As you can see. It is always positive. so the range is: