Simplifying
cos(5x) + cos(2x) = 0
(5x)
cos * 5x + cos(2x) = 0
5cos * x + cos(2x) = 0
Multiply cos * x
5cosx + cos(2x) = 0
(2x)
5cosx + cos * 2x = 0
5cosx + 2cos * x = 0
Multiply cos * x
5cosx + 2cosx = 0 5cosx + 2cosx = 7cosx
7cosx = 0
Solving
7cosx = 0
Solving for variable 'c'. cosx = 0
Simplifying
cosx = 0
Hope this helps!
In short your answer is 0
