1. The problem is to evaluate the expression $\sqrt[]{}$, which is an incomplete square root notation. 2. The square root symbol $\sqrt{}$ requires a number or expression inside the radical to evaluate. 3. Since the expression inside the square root is missing, it is undefined and cannot be evaluated. 4. To solve a square root problem, you need a number or expression inside the radical, for example, $\sqrt{9} = 3$ because $3^2 = 9$. 5. Please provide a complete expression inside the square root for evaluation.