Negative Square Root Graph. Transformations of Radical Functions: x y. 0. 1. 2. 3. 4. 0. -1. -. -2. Graph of "a" Times Square Root.
If you are forgetting the basics on radical simplification then you should definitely check this link.
Expressing in simplest radical form just means simplifying a radical so that there are no more square roots, cube roots, 4th roots, etc left to find.