Q. If $8 cos 2 θ + 8 sec 2 θ = 65, 0 < θ < \frac{π}{2}$ , then the value of $4 cos 4 θ$ is equal to

1666 230 KEAMKEAM 2011Trigonometric Functions Report Error

A

$\frac{- 33}{8}$

B

$\frac{- 31}{8}$

C

$\frac{- 31}{32}$

D

$\frac{- 33}{32}$

E

$\frac{- 31}{4}$

Solution:

Correct answer is (b) $\frac{- 31}{8}$