Homework Help: Parametric Equation to Cartesian

1. Sep 5, 2011

SoftOath

1. The problem statement, all variables and given/known data
Find a Cartesian equation relating x and y corresponding to the parametric equations

$x = \frac{2t}{t^3+1}$

$y = \frac{9t^2}{t^3+1}$

$t \neq -1$

Write your answer in the form $P(x,y)=0$,
where $P$ is a polynomial in $x$ and $y$ such that the coefficient of $x^3$ is $729$.

2. The attempt at a solution

So I already have the second part of the question done which is finding the tangent line at a point, which I solved using dy/dt and dx/dt. I just cannot for the life of me figure out how to start this problem. I have tried solving for t and that has failed miserably. If anyone could just give me a little aid on how to get started, I could most likely solve it from there. Cheers.

Last edited: Sep 5, 2011
2. Sep 5, 2011

LCKurtz

Divide y by x to get t = (2/9)(y/x) and put that in for the t's.

3. Sep 5, 2011

SoftOath

Many thanks friend. Got this solved.