# Parametric Representation of a curve

• April 17th 2008, 12:57 PM
MathNeedy18
Parametric Representation of a curve
Obtain cartesian equation of the curve

x= 2cos^(2)r
y= 3sin^(2)r

0 less than/equal R less than/equal to 2 pi

I dont know what to do....! Help me please!
• April 17th 2008, 03:00 PM
o_O
$x = 2\cos^{2} r \quad \Rightarrow \quad \frac{x}{2} = \cos^{2} r$

$y = 3\sin^{2} r \quad \Rightarrow \quad \frac{y}{3} = \sin^{2} r$

$\frac{x}{2} + \frac{y}{3} = \underbrace{\cos^{2} r + \sin^{2} r}_{1}$

etc.

Make sure you pay attention to the restriction of r and how it affects the domain and range of the cartesian curve.