Level:
Project ID:
2010010701
Source Problem:
Accepted:
0
Clonable:
1
Easy:
1
The solution set of the equation \( \cos x =-0.5 \) for \( x\in[ 0,2\pi ]\) is:
\( \left\{ \frac{2\pi}3,\frac{4\pi}3\right\} \)
\( \left\{ \frac{2\pi}3,\frac{5\pi}3\right\} \)
\( \left\{ \frac{4\pi}3,\frac{5\pi}3\right\} \)
\( \left\{ \frac{4\pi}3,\frac{7\pi}3\right\} \)