Given data:
The given expression is cosx=-1/2.
The solution of the given expression is,
[tex]\begin{gathered} \cos x=-\cos \frac{\pi}{3} \\ \cos x=\cos (\frac{2\pi}{3}) \\ x=\frac{2\pi}{3}or120^{\circ} \end{gathered}[/tex]
Thus, the value of x is 2π/3 or 120 degrees.
