Explain Even function

Let us study about Even function and odd function,

Even function

A function f : AB is said to be an even function if
f(x) = f(-x) for all xA.

how to find domain and range of f depends on the definition of the function.
Examples of even function are

y = cosx, y = x2, y = secx
A polynomial with only even powers of x is an even function.


I hope the above explanation was useful.