Even and Odd Functions

Even Function - Symmetry about the Vertical Axis

A function, f, is symmetrical about the vertical axis when all the values of x in the domain are verified:

f(−x) = f(x)

The functions that are symmetrical about the vertical axis are called even functions.

Even Function

Even Function

Graph of Even Function

Odd Function - Symmetry about the Origin

A function, f, is symmetrical about the origin if all values of x in the domain are verified:

f(−x) = −f(x)

The symmetrical functions about the origin are called odd functions.

Odd Function

Odd Function

Graph of Odd Function