70 likes | 226 Views
Photo by Greg Kelly, 2005. Greg Kelly, Hanford High School, Richland, Washington. 1.4 Parametric Equations. Mt. Washington Cog Railway, NH. We can do this by writing equations for the x and y coordinates in terms of a third variable (usually t or ).
E N D
Photo by Greg Kelly, 2005 Greg Kelly, Hanford High School, Richland, Washington 1.4 Parametric Equations Mt. Washington Cog Railway, NH
We can do this by writing equations for the x and y coordinates in terms of a third variable (usually t or ). There are times when we need to describe motion (or a curve) that is not a function. These are called parametric equations. “t” is the parameter. (It is also the independent variable)
WINDOW GRAPH To graph on the TI-89: ENTER ENTER Y= Example 1: MODE Graph……. 2 PARAMETRIC 2nd T )
Hit zoom square to see the correct, undistorted curve. We can confirm this algebraically: parabolic function
Circle: If we let t = the angle, then: Since: We could identify the parametric equations as a circle.
WINDOW GRAPH Y= Graph on your calculator: Use a [-4,4] x [-2,2] window.
Ellipse: This is the equation of an ellipse. p