Quiz 3：94政大資管所考題觀摩

Let \(f(x) = \left\{ {\begin{array}{*{20}{c}}{\frac{{\sqrt {x + 4} - 3}}{{x - 5}}\;\;\;\;if\;x \ne 5}\\{\;\quad \;\,\,c\;\;\quad \quad \quad if\;x = 5}\end{array}} \right. \) ，and let \(f\) be continuous at \(x = 5\). Then \(c\) =?