sin(x) and cos(x) have period 2pi. tan(x) and cot(x) have period pi. |sin(x)| and |cos(x)| have period pi. $sin^2$(x) and $cos^2$(x) have period pi. The period of asin(bx + c) is 2*pi/|b|. For combinations, the period is the LCM of individual periods (if it exists).