The angle of intersection of the curves $y=2 \sin ^{2} x$ and $y=\cos ^{2} x$ at $x=\frac{\pi}{6}$ is
A. $\frac{\pi}{4}$
B. $\frac{\pi}{2}$
C. $\frac{\pi}{3}$
D. $\frac{\pi}{6}$
Given that the curve $y=2 \sin ^{2} x$ and $y=\cos ^{2} x$
Differentiating both w.r.t. $x$,
$\frac{d y}{d x}=4 \sin x \cos x$ and $\frac{d y}{d x}=-2 \cos x \sin x$
$\mathrm{m}_{1}=4 \sin \mathrm{x} \cos \mathrm{x}$ and $\mathrm{m}_{2}=-2 \cos \mathrm{x} \sin \mathrm{x}$
$\operatorname{At} \mathrm{X}=\frac{\pi}{6}$
$\mathrm{m}_{1}=\sqrt{3}$ and $\mathrm{m}_{2}=-\frac{\sqrt{3}}{2}$
$\tan \theta=\left|\frac{\mathrm{m}_{1}-\mathrm{m}_{2}}{1+\mathrm{m}_{1} \mathrm{~m}_{2}}\right|$
$\Rightarrow \tan \theta=\left|\frac{\sqrt{3}+\frac{\sqrt{3}}{2}}{1-\sqrt{3} \times \frac{\sqrt{3}}{2}}\right|=\frac{\frac{3 \sqrt{3}}{2}}{\frac{1}{2}}=3 \sqrt{3}$
$\Rightarrow \theta=\tan ^{-1} 3 \sqrt{3}$