Hello!
The answer is: [-2,2]
Why?
The range of a function shows where the function can exist in the y-axis.
To know the range of the function, we have to isolate x,
So

The only possible values that y can take go from -2 to 2. Taking values out of these values will give as result a non-real number.
Therefore,
The range of the function is [-2,2]
Have a nice day!