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AP EAMCET · Maths · Trigonometric Ratios & Identities

If \(\left(\frac{\sin 3 \theta}{\sin \theta}\right)^2-\left(\frac{\cos 3 \theta}{\cos \theta}\right)^2=a \cos b \theta\), then \(a: b=\)

  1. A \(4: 1\)
  2. B \(8: 1\)
  3. C \(3: 2\)
  4. D \(2: 1\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(4: 1\)

Step-by-step Solution

Detailed explanation

\( \left(\frac{\sin 3 \theta}{\sin \theta}\right)^2-\left(\frac{\cos 3 \theta}{\cos \theta}\right)^2 = \frac{\sin^2 3\theta \cos^2\theta - \cos^2 3\theta \sin^2\theta}{\sin^2\theta \cos^2\theta} \)…