2 ∫ (cos^2 x - sin^2 x)/(cos^2 x + sin^2 ​​​​​​​x) . dx =

Question

\(2\int \frac{cos^2\,x - sin^2\,x}{cos^2\,x + sin^2\,x} . dx =\)

2 ∫ (cos²x - sin²x)/(cos²x + sin²x) . dx =

(a) sin 2x + c 

(b) cos 2x + c 

(c) tan 2x + c 

(d) 2 sin 2x + c

Answer 1

Correct answer is (a) sin 2x + c