## Precalculus (6th Edition) Blitzer

Curves that are not graphs of the functions are not easy to describe. Parametric equations make the interpretation of such curves easier. For example: Let us consider the equation of a circle. Parametric equations of a circle are provided by \begin{align} & x=a\sin t \\ & y=a\cos t \\ \end{align} Where “a” is the radius of the circle. Parametric equations make this interpretation easier. Thus, the provided statement makes sense.