What are all solutions of equation cos x=-0.5, in the set [0,2pi)? (Provide the answer in radians).

We'll have to determine all possible values for x, located
in the interval [0,2pi), that makes the value of cosine function
-0.5.

We'll write the values -0.5 =
-1/2

The cosine function is negative in the 2nd and the 3rd
quadrants.

x = arccos(-1/2)

x
= pi - pi/3

x = 2pi/3 (2nd
quadrant)

x = pi + pi/3

x =
4pi/3 (3rd quadrant)

The possible values for
x, in radians, located in the set [0,2pi), are: {2pi/3;
4pi/3}.