A rectangular equation, or an equation in rectangular form is an equation composed of variables like and which can be graphed on a regular Cartesian plane. For example is a rectangular equation.
A curve in the plane is said to be parameterized if the set of coordinates on the curve, , are represented as functions of a variable .
These equations may or may not be graphed on Cartesian plane.
Find a set of parametric equations for the equation .
Assign any one of the variable equal to . (say = ).
Then, the given equation can be rewritten as .
Therefore, a set of parametric equations is = and .
Eliminate the parameter and find the corresponding rectangular equation.
Rewrite the equation as in terms of .
Now, replace by ( ) in the equation .
Therefore, the corresponding rectangular equation is .
There is another type of equations called polar equations which need to be graphed on a polar plane .