Question

Evaluate the d^3f/dx^3 of f(x)=sin(x)cos(x)

Answer 1

$f(x)=sin(x)cos(x)=\frac{1}{2}sin(2x)\\ \frac{df}{dx}=cos(2x)\\ \frac{d^2f}{dx^2}=-2sin(2x)\\ \frac{d^3f}{dx^3}=-4cos(2x)$