See also: Graph

In Set theory, the graph of a function or graph ensemblist G of a correspondence $\backslash \; mathfrak\; \{C\}\; \backslash ,$ whose starting whole is called E and the whole of arrival F , is the Sous-ensemble of E × F formed by the couple S of elements bound by the correspondence:

$G\; =\; \backslash \; \{(X,\; there)\; \backslash \; in\; E\; \backslash \; times\; F\; \backslash ,|\backslash ,\; X\; \backslash \; mathfrak\; \{C\}\; there\; \backslash ,\; \backslash \}\; \backslash ,$

The unit G is called graph $\backslash \; mathfrak\; \{C\}$ because it makes it possible to give a chart of it: indeed, if one can represent E and F on two secant axes, each couple of G can then be represented by a point in the plan defined by the two axes. For example, a numerical Fonction (of $\backslash \; mathbb\; \{R\}$ in $\backslash \; mathbb\; \{R\}$) can be represented by a plane curve; one also speaks about curve représentatrice of the function.

Note: if the correspondence is a function whose starting whole is a Cartesian square , it is preferable to represent E like a plan and not an axis. In this case, the function is represented by a left surface in usual space with 3 dimensions.

It is possible then to be brought back to a plane representation by considering level line , i.e. by drawing in the starting plan a altimetric Carte of the Relief of left surface.

See too

Related articles

• Correspondence and relation
• Study of function
• Chart

External bonds

• FooPlot - to trace graphs for mathematical functions in 2D and 3D