Hello.

when you see the\theta which is unknown

i need to solve the following by Moivres theorem

r^3(cos 3\theta + i sin 3\theta )=1..how can i find the \theta ?

i thought that the Real part equals 1 as you can see...and the imaginary part is 0 since is not there...so

r^3 cos3\theta =1

r^3 sin3\theta =0

so to find the angle \theta i tried r^3 sin3\theta devided by r^3 cos3\theta equals 0 devided by 1...then the next step would be sin3\theta devided cos3\theta equals 0...therefore tan3\theta =0...from now on i am stuck...but i am not sure it was the right step to follow...any advices how to get ahead?