The period of the function where [⋅] denotes the greatest integer function is then k=
Since cos 2x is a periodic function with period
therefore sin2x is periodic with period 1. (1)
x – [x] is a periodic function with period 1. (2)
Since, cos 4x is a periodic function with period
= 1/2and cos 2x is a periodic function with period
therefore, period of sin4x is equal to
From Eq. (1), (2) and (3), we get
Period of