Question

Find all solutions to the equation. cos x = - 1/2

Answer 1

`x = 2\pi /3 + 2\pi n\\x= 4\pi /3 + 2\pi n`

Explanation:

Radian: x = 2\pi /3 + 2\pi n\\x= 4\pi /3 + 2\pi n

Degree: x = 120 + 360n , x = 240 + 360n