ExamBro
ExamBro
WBJEE · Maths · Trigonometric Ratios & Identities

If \(\theta \in\left(\frac{\pi}{2}, \frac{3 \pi}{2}\right)\) then the value of \(\sqrt{4 \cos ^{4} \theta+\sin ^{2} 2 \theta}+4 \cot \theta \cos ^{2}\left(\frac{\pi}{4}-\frac{\theta}{2}\right)\) is

  1. A \(-2 \cot \theta\)
  2. B \(2 \cot \theta\)
  3. C \(2 \cos \theta\)
  4. D \(2 \sin \theta\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(2 \cot \theta\)

Step-by-step Solution

Detailed explanation

\(\sqrt{4 \cos ^{4} \theta+\sin ^{2} 2 \theta}+4 \cot \theta \cos ^{2}\left(\frac{\pi}{4}-\frac{\theta}{2}\right)\) \(=\sqrt{4 \cos ^{4} \theta+(2 \sin \theta \cos \theta)^{2}} +2 \cot \theta\left[2 \cos ^{2}\left(\frac{\pi}{4}-\frac{\theta}{2}\right)\right]\)…