The function of time representing a simple harmonic motion with a period of ${\pi \over \omega }$ is :
cos($\omega$t) + cos(2$\omega$t) + cos(3$\omega$t)
sin2($\omega$t)
sin($\omega$t) + cos($\omega$t)
3cos$\left( {{\pi \over 4} - 2\omega t} \right)$
