This involves a quick application of the power rule, which is [tex]f'(x)=nx^{n-1}[/tex].
First, it is helpful to rewrite [tex]f(x)=\sqrt{x}[/tex] as [tex]f(x)=x^{\frac{1}{2}}[/tex]. Remember that these are equivalent forms, but the latter is easier to use with the power rule.