Square root and x-th root

The root key comes before the number. Press , type 49, and press . For $\displaystyle \sqrt[4]{81}$, the index comes first: type 4, press , then , the orange label above $\displaystyle y^{x}$, and type 81. Press : $\displaystyle 7-3$ is 4..

▶ Watch this step in the video (20:10)