Question

solve it cos 120°=?

Answer 1

D€AR FRI€ND ,,

Here is your answer=>>>>

Cos 120°= Cos (180-60) = -Cos 60°
We know that,
Cos 60= 1/2
then,-Cos60°= -1/2

Answer 2

Hey friend your answer is
$cos \: 120 \\ = cos(90 + 30) \\ = - sin \: 30 \\ = - \frac{ 1 }{2}$