Question

please solve this question

Answer 1

Hi ,

tan 60° = √3 ----( 1 )

It is given that ,

( 1 - tan² 60° )/(1 + tan² 60° ) = cosx

[ 1 - ( √3 )² ]/[ 1 + ( √3 )² ] = cosx

( 1 - 3 )/ ( 1 + 3 ) = cosx

-2/4 = cosx

-1/2 = cosx

cos 120 = cos x

Therefore ,

120° = x

x = 120°

I hope this helps you.

: )