Question

2√3 cos (theta/2)=-3

Answer 1

2√3 cos (theta/2)=-3
cos (theta/2)=-3/(2√3)
cos (theta/2)= -√3/2

Answer 2

cos (theta/2) = -cos60
cos (theta/2) = cos(180-120)
cos (theta/2) = cos120
theta /2 = 120
theta =240

Answer 3

thanks so much!