# variable

A variable is an algebraic quantity whose numerical value may change. The most-used symbols
in elementary algebra are *x* and *y*. If one variable is
a function of the other, as in the equation *y* = *ax*^{2} + *bx* + *c*, where *a*, *b*, and *c* are constants,
then *y* is termed the **dependent variable**, since
its value depends on the value of the **independent variable** *x*. See also parameter.