I am having a little trouble. I am asked to evaluate the fourier transform of a periodic train of triangle shaped pulses. Then I have to evaluate the power spectral density. Now it is very easy to find the fourier transform of one of the triangles, but what do I do when it is periodic? Do I have evaluate the signal with the fourier series and using the relationships between the magnitude of Dn to find the mag. of F(w) and then get the spectral density?