1) $\int\frac{dx}{\cos 2x-\cos^{2}x}=$ A) - tan x+c B) cot x+ c C) tan x+c D) - cot x+c Answer: Option BExplanation: We have, l= $\int\frac{dx}{\cos 2x-\cos^{2}x}$ $l=\int\frac{dx}{2\cos ^{2}x-1-\cos^{2}x}$ $l=\int\frac{dx}{-\sin^{2}x}$ $l=-\int cosec^{2}x dx$ l= cotx +c
