Answer:
θ = 240
and
cos(θ) = -0.5
Step-by-step explanation:
Theta is in the third quadrant, that meansit goes from 180 to 270 degrees
Then,
cos^2 (θ) =1/4
cos (θ) = ± 1/2
θ = arccos(0.5)
θ = 60
But in the third quadrant
θ = 180 + 60 = 240
θ = 240
and
cos(θ) = -0.5
