# Parametric Equation

Pronunciation: /ˌpær.əˈmɛ.trɪk ɪˈkweɪ.ʃən/ Explain

A parametric equation is a set of equations with more than one dependent variables. Figure 1 is an example of a parametric equation.

 y = t - 1x = 2t + 2Figure 1 - Example of a parametric equation.

In figure 1, both y and x are dependent variables. The independent variable is t in both cases. For a set of equations to be a parametric equation, all dependent variables (x and y in this case) must depend on the same independent variable (t in this case).

Parametric equations are used in physics to describe the location of particles over time. They are useful whenever more than one dependent variable depends on an independent variable.

Figure 2 is an example of a graph of a parametric equation.

 Click on the blue points on the sliders to change the figure. Manipulative 1 - Parametric Equation Created with GeoGebra.

1. McAdams, David E.. All Math Words Dictionary, parametric equation. 2nd Classroom edition 20150108-4799968. pg 135. Life is a Story Problem LLC. January 8, 2015. Buy the book
2. parametric equation. merriam-webster.com. Encyclopedia Britannica. Merriam-Webster. Last Accessed 12/3/2018. http://www.merriam-webster.com/dictionary/parametric equation. Buy the book

McAdams, David E. Parametric Equation. 4/27/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/p/parametricequation.html.

### Revision History

4/27/2019: Changed equations and expressions to new format. (McAdams, David E.)