Solve the Equation For $\theta$ $( 0 \leq \theta \leq 2 \pi )$

Multiple Choice

Solve the equation for $\theta$ $( 0 \leq \theta \leq 2 \pi )$ . For some of the equations you should use the trigonometric identities listed in this section. Use the trace feature of a graphing utility to verify your results. $\cos 2 \theta + 3 \cos \theta + 2 = 0$

A) $\frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 } , \pi$
B) $\frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 } , 2 \pi$
C) $0 , \frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 } , \pi$
D) $0 , \frac { \pi } { 3 } , \frac { 4 \pi } { 3 }$
E) $0 , \frac { \pi } { 3 } , \frac { 4 \pi } { 3 } , \pi$