Question

If sin β is the GM between sin a and cos a, then cos 2β is equal to

• A. \(2sin^2=(\frac{\pi}{4}-a)\)
• B. \(2cot^2=(\frac{\pi}{4}-a)\)
• C. \(2cos^2=(\frac{\pi}{4}-a)\)
• D. \(2sin^2=(\frac{\pi}{4}+a)\)

Answer 1

The Correct Option is A

The correct answer is(A): \(2sin^2=(\frac{\pi}{4}-a)\)