The command '\sqrt{...}' describes square root where the dots is for radicand. Lets see on example:

x^{\frac{1}{2}} = \sqrt{x}

Beside the mentioned form, a root can be described by '\sqrt[...]{...}' command. In this case the first dots stands for the root's degree and the second is for radicand.

x^{\frac{1}{3}} = \sqrt[3]{x}

To test the mastery of the material write one of the roots of a quadratic equation in TeX format: