Use Identities to Solve Trigonometric Equations
Solve the Equation on the Interval

Multiple Choice

Use Identities to Solve Trigonometric Equations
Solve the equation on the interval [0, 2π) .
- $$\cos \left( x + \frac { \pi } { 3 } \right) + \cos \left( x - \frac { \pi } { 3 } \right) = 1$$

A) 0
B) $\frac { \pi } { 2 } , \frac { \pi } { 6 }$
C) $\frac { \pi } { 6 } , \frac { \pi } { 4 }$
D) $\frac { \pi } { 2 } , \frac { \pi } { 4 }$