Question

d/dx 4cos2x solve this

Answer 1

$\frac{d}{dx} (4 \cos(2x)) \\ \\ = 4 \frac{d}{dx} \cos(2x) \\ \\ = - 4 \sin(2x) \frac{d}{dx} (2x) \\ \\ = - 4 \times 2( \sin(2x) ) \\ \\ = - 8 \sin(2x) \\ \\ \\ hope \: it \: helps...$