Q. $\frac{1 - t a n ^{2} 1 5 ^{\circ}}{1 + t a n ^{2} 1 5 ^{\circ}} =$

4582 252 COMEDKCOMEDK 2010Trigonometric Functions Report Error

A

$1$

25%

B

$3$

22%

C

$\frac{3}{2}$

47%

D

$2$

7%

Solution:

$\frac{1 - t a n ^{2} 1 5 ^{\circ}}{1 + t a n ^{2} 1 5 ^{\circ}} = cos (2 (1 5^{\circ}))$
$= cos 3 0^{\circ} = \frac{3}{2}$