A function is a connection between an independent variable $(X)$ and a dependent variable $(Y)$. The relationship between the variables is called a "correspondence rule".

**An algebraic representation of a function is actually a description of the relationship between the dependent variable** **$(Y)$**** and the independent variable** **$(X)$**** by means of an equation.**

The following is the typical structure of a graphical representation:

- $Y=X+3$, $Y=2X-5$