The equations

x = 4t and y = 2 - 10t - 5t^2

can represent the path of a projectile. They are called parametric equations and t is the parameter.

x = 4t and y = 2 - 10t - 5t^2

can represent the path of a projectile. They are called parametric equations and t is the parameter.

## Software/Applets used on this page

## Glossary

### parameter

a) a constant or variable term in a function that determines the specific form of the function but not its general nature, as a in f(x) = ax, where a determines only the slope of the line described by f(x).

b) one of the independent variables in a set of parametric equations.

b) one of the independent variables in a set of parametric equations.

### parametric equations

a pair of equations x=u(t) and y=v(t) where t is a parameter, that describe a curve.

### path

A finite sequence of edges such that the end vertex of one edge in the sequence is the start vertex of the next and in which no vertex appears more than once.

### projectile

a body moving in a gravitational field under free fall

### union

The union of two sets A and B is the set containing all the elements of A and B.