If $\int f(x)dx=-\cos\sqrt{x}+c$, then f(x) =

$\sin \sqrt{x}$ $\frac{\sin \sqrt{x}}{\sqrt{x}}$ $2\cos \sqrt{x}$ None of these

None of these

$\int f(x)dx=-\cos\sqrt{x}+c$ so differentiate on both sides wrt x $f(x)=\frac{\sin \sqrt{x}}{2\sqrt{x}}$