Question

if tan = 1/√ 3 then cos 2 theta = ?​

Answer 1

Step-by-step explanation:

tan A=1/Root 3

tan 30=1/Root 3

A=30

cos 2×A

cos2×30=cos 60

=1/2

hope it may helps u....

Answer 2

Answer:

$\tan( \alpha ) = \frac{1}{ \sqrt{3} } \\ \\ \cos(2 \alpha ) = \frac{1 - { \tan}^{2} \alpha }{ 1+ { \tan }^{2} \alpha } \\ \\ = \frac{ 1 - \frac{1}{3} }{1 + \frac{1}{3} } = \frac{ \frac{2}{3} }{ \frac{4}{3} } = \frac{2}{4} = \frac{1}{2}$