parametric equations

noun Mathematics.

1. one of two or more equations expressing the location of a point on a curve or surface by determining each coordinate separately.

pl n

1. a set of equations expressing a number of quantities as explicit functions of the same set of independent variables and equivalent to some direct functional relationship of these quantitiesa circle x²+y²=r² has parametric equations x=r cos θ and y=r sin θ in terms of the parameters r and θ