I.E.S. “Andrés de Vandelvira” Sección Europea
Mathematics
2 Functions 2.1 Definition. A function is a relation between two variables called x and y in which: • • •
x is the independent variable y is the dependent variable Every x -value is related to one and only one y-value.
Functions can be represented using grids and points. This is important when the function behaviour needs to be visualized. But be careful, because there are graphs which are not functions. For example:
In the second case, for example the x-value -1 has three different correspondences, so, it is not a function.
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