seems right to me
Solve the trig equation..
1-9*cos^2 (2x) = 0
My Work:
1-9*cos^2 (2x)
cos^2 (2x) =1/9
cos (2x) =1/3 or -1/3
2x=arccos(1/3)
x=0.5*arccos(1/3)
or
2x=arccos(-1/3)
x=0.5*arccos(-1/3)
Is this correct? When I plug the value of x into the given trig equation, I do not get 0 = 0.