Use chain, logarithmic, product and quotient differentiation

Differentiate the following expressions with respect to $x$, simplifying your answers whenever possible.

(a) $\tan^{-1}(e^{3x})$,2 marks

(b) $5^{2x}$,2 marks

(c) $\dfrac{ax}{\sqrt{x^3+1}}$, where $a$ is a constant.3 marks