Answer
The derivative is $\frac{3}{\sqrt x}-5sin(x)$.
Work Step by Step
To find the derivative just apply the product rule$((x^n)'=nx^{n-1})$ on the individual terms as follows: $f'(x)=(6\sqrt x+5cos(x))'=(6\sqrt x)' + (5cos(x))'=$ $(6)(\frac{1}{2\sqrt x})+(5)(-1)(sin(x))= \frac{3}{\sqrt x}-5sin(x)$.
