বৃহস্পতিবার, ৩ ফেব্রুয়ারী, ২০১১

Periodic function

A function that repeats itself after certain interval is called a periodic function. A common example of periodic function is sine or cosine. We know sine0=0;sine90=1;sine180=0;sine270=-1;sine360=0;sine450=1 and so on.That means the value of sine repeats its value after every 360 degree.That is why sine function is called a periodic function.Here 360 degree is called the period.
Mathematically we can write
say f(x) is a function and f(x)=sinex Then
f(x)=f(x+360)=f(x+360+360)=...
or f(x)=f(x+360)=f(x+720)=...