Question

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

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

Answer 1

Answer: (C)

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