# Coordinate system

To illustrate functions or to draw **graphs** in gerneral, it requires a **coordinate system**.

## Cartesian coordinate system

In math we use the **cartesian coordinate system**.

For that we need coordinate axes, meaning two perpendicular staight lines. These are our two **axes**.

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### Remember

The vertical axis is the

**y-axis**or**ordinate**. The**x-axis**can also be called as**abscissa**.If only the positive values are important, a coordinate system can also look like this:

i

### Hint

It is very important that you do not interchange the two axes!

In the coordinate system, you also only draw the arrows in the positive direction.

In the coordinate system, you also only draw the arrows in the positive direction.

## Quadrants

As you can see a coordinate system is divided into four quaters, called **quadrants**, by the axes.

The naming is done **counter-clockwise**.