Math Relationships Coordinate system and relationship graph

# Graphical representation of relationships

Relationships can also be graphically displayed.

## Coordinate system

By drawing in two vertical lines, one obtains a coordinate system.

!

### Remember

Usually, the Cartesian coordinate system is used.

The upward axis is the y-axis or ordinate. The x-axis is also called abscissa.

## Graph of an relationship

For relationships we have different value pairs. We can draw these as points and get the relationship graph.

!

### Remember

The order of the values of a point $P(x|y)$ is important. Note: always first x, then y.

### Example

Weight (in kg)Price (in €)
14
28
312

The table gives the following points:

$(1|4)$, $(2|8)$ and $(3|12)$

i

### Hint

Watch out for a meaningful scale.