- #1
Helly123
- 581
- 20
Homework Statement
cos2x + cos x = 0 (0 <= x <= 360)
Homework Equations
The Attempt at a Solution
cos2x + cos x = 0
2cos(3x)/2 cos(x)/2 = 0
3x/2 = 90 degrees
x = 60 degrees
x/2 = 90
x = 180
3x/2 = 270
x = 180
x/2 = 270
x = 540 (not qualified)
is there any more possibility (answers) for x?