A Level

MATHEMATICS · Single correct · A Level · Mathematics · Trigonometry · Trigonometry

Problem

\frac{d}{dx} \left(\frac{\cot^2 x - 1}{\cot^2 x + 1}\right) =

(a)

-\sin 2x

(b)

2\sin 2x

(c)

2\cos 2x

(d)

-2\sin 2x