Use inverse functions where needed to find all solutions (if they exist)of the given equation on the interval [0,2π). $2 \cos ^ { 2 } x - \cos x - 1 = 0$
A) $x = \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
B) $x = 0 , \frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 }$
C) $x = 0 , \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
D) $x = \frac { \pi } { 3 } , \pi , \frac { 5 \pi } { 3 }$
E)solution does not exist

Question

Use inverse functions where needed to find all solutions (if they exist)of the given equation on the interval [0,2π).​ $2 \cos ^ { 2 } x - \cos x - 1 = 0$ ​
A)​ $x = \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
B) $x = 0 , \frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 }$
C) $x = 0 , \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
D) $x = \frac { \pi } { 3 } , \pi , \frac { 5 \pi } { 3 }$
E)​solution does not exist

Quizplus · Accepted Answer

The Answer of Use inverse functions where needed to find all solutions (if they exist)of the given equation on the interval [0,2π).​ $2 \cos ^ { 2 } x - \cos x - 1 = 0$ ​
A)​ $x = \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
B) $x = 0 , \frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 }$
C) $x = 0 , \frac { \pi } { 3 } , \frac { 2 \pi } { 3 }$
D) $x = \frac { \pi } { 3 } , \pi , \frac { 5 \pi } { 3 }$
E)​solution does not exist

Use Inverse Functions Where Needed to Find All Solutions (If 2cos⁡2x−cos⁡x−1=02 \cos ^ { 2 } x - \cos x - 1 = 02cos2x−cosx−1=0

Use Inverse Functions Where Needed to Find All Solutions (If $2 \cos ^ { 2 } x - \cos x - 1 = 0$