Question

Find the derivative:

$\frac{\cos 2x}{\sqrt{2x^2-7}}$

Answer 1

$\frac{\cos 2x}{\sqrt{2x^2-7}}=\frac{-2\sin 2x\sqrt{2x^2-7}-\cos 2x\frac{4x}{\sqrt{2x^2-7}}}{2x^2-7}=\frac{2(7-2x^2)\sin 2x-4x\cos 2x}{(2x^2-7{)}^{3/2}}$