Question 581349
1 - cos(theta) = 1/2

- cos(theta) = 1/2 - 1

- cos(theta) = -1/2

cos(theta) = (-1/2)/-1

cos(theta) = 1/2

In the interval 0 to 2pi, cos(theta) = 1/2 has the radian value of pi/3 and also 5pi/3.