Question

if $y={\left(\cos x^2\right)}^2$, then $\frac{dy}{dx}$ is equal to

• A. $-4x\sin 2x^2$
• B. $-x\sin x^2$
• C. $-2x\sin 2x^2$
• D. $-x\cos 2x^2$

Answer 1

Answer: (C)

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