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.
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.
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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 €) |
|---|---|
| 1 | 4 |
| 2 | 8 |
| 3 | 12 |
The table gives the following points:
$(1|4)$, $(2|8)$ and $(3|12)$
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Hint
Watch out for a meaningful scale.