Variable
This is an old revision of this page, as edited by Jaques (talk | contribs) at 19:49, May 14, 2007. It may differ significantly from current revision.
In mathematics, a variable is a value which usually is the subject or part of a function and must be subject to change while not affecting the structure behind the function in which it acts.
For example, if we have a function: <math>f(x,y)=x^{2}+3y</math>, then <math>x,y</math> are said to be the variables of the function, <math>f</math>.
Further, <math>f(1,2)=(1)^{2}+3(2)=1+6=7</math>. We change the variable and thus alter the value of the function.
The set of all variables upon which a function acts is said to be the domain. The set of all values that a function can take due to its domain is called its range.