Parametric Equation. Namely, x = f ( t ), y = g ( t ) t D. where D is a set of real numbers. The variable t is called a parameter and the relations between x, y and t are called parametric equations. The set D is called the domain of f and g and it is the set of values t takes.
Parametric equation is in syllabus of AP calculus as well as in A-level mathematics . It also in SAT test Math level -2.
Parametric Equations So far, the graphs we have drawn are defined by one equation: a function with two variables, x and y. In some cases, though, it is useful to introduce a third variable, called a parameter, and express x and y in terms of the parameter. This results in two equations, called parametric equations.
Worksheet on Parametrics and Calculus-2