If $$ f(x) = \sqrt{x} $$ , then $$ f(64) = \underline{\quad}...

Question Analysis
This question tests the ability to evaluate a square root function at a specific value, which is an intermediate skill in Algebra-1.

Key Concept Explanation
To evaluate a function at a specific value, substitute the value into the function and simplify.

Step-by-step Solution
1. Identify the function:
2. Substitute :