Parametric Equation to Cartesian

SoftOath
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Homework Statement


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.
 
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Divide y by x to get t = (2/9)(y/x) and put that in for the t's.
 
Many thanks friend. Got this solved.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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