# *Periodic functions A function is said to be periodic if it repeats itself after a fixed period. For a periodic function f (x) there exists a positive number ‘p’ such that

***Periodic functions**

A function is said to be periodic if it repeats itself after a fixed period. For a periodic function f (x) there exists a positive number ‘p’ such that

f (x + p) = f (x) for all x.

The smallest such value of ‘p’ is called period.

Periodicity of tan θ & cot θ is π & that of sinθ, cosθ, cscθ and secθ is 2π.