## Increasing and decreasing functions

**A function of increasing**

if ,

for all of the region definitions (with the increase of the argument the corresponding points of the graph ascending stems)

**The function of the descending**

if ,

for all of the region definitions (with the increase of the argument the corresponding points of the graph omitted)

## Even and odd functions

**Function even**

for all of the region definitions. The graph of an even function is symmetrical to the axis vanocni

**A function is odd**

for all of the region definitions. The graph of an odd function is symmetric vanocni the origin.

## The frequency

**Definition: **a Function is called periodic with period if for any of the determining function of the number and also belong to the scope and the validity of the equation

.

Through the gaps in length of the graph of a periodic function repeats itself.

### Period features

Functions have period .

Functions have period .