Question

$y=\sin x\cos x$ find $\frac{dy}{dx}$

Answer 1

$y=\sin x\cos x\frac{dy}{dx}=\frac{d}{dx}\sin x\cos x\frac{dy}{dx}=\sin x(-\sin x)+\cos x\left(\cos x\right)\frac{dy}{dx}={\cos }^{2}x-{\sin }^{2}x=\cos 2x$