Answer:
x = [tex]\frac{4\pi }{3}[/tex]
Step-by-step explanation:
given
cos(x - [tex]\frac{\pi }{3}[/tex]) = - 1, then
x - [tex]\frac{\pi }{3}[/tex] = [tex]cos^{-1}[/tex](- 1) = π
Add [tex]\frac{\pi }{3}[/tex] to both sides, hence
x = π + [tex]\frac{\pi }{3}[/tex] = [tex]\frac{4\pi }{3}[/tex]