Question

find the two values for x(in radians between 0 & 2pii),that satisfy the equation cos x=-1/2

Answer 1

Given data:

The given expression is cosx=-1/2.

The solution of the given expression is,

$\begin{gathered} \cos x=-\cos \frac{\pi}{3} \\ \cos x=\cos (\frac{2\pi}{3}) \\ x=\frac{2\pi}{3}or120^{\circ} \end{gathered}$

Thus, the value of x is 2π/3 or 120 degrees.