Find rectangular equation from parametric equation??? Find rectangular equation from parametric
$ x = t^{2} + t $
$ y = t^{2} - t $ 
I tried finding the equation but I am stuck here:
$ x - t^{2} = t $ 
$ y = t^{2} - t $
$ y = t^{2} - ({x - t^{2}}) $
$ y = t^2 - x + t^2  $
$y = 2t^2 - x $ 
Is there even a parametric equation for this?

We have $$x+y=2t^2\iff t^2=\frac{x+y}2, x-y=2t\iff t=\frac{x-y}2$$
$$\implies\left(\frac{x-y}2\right)^2=\frac{x+y}2\iff (x-y)^2=2(x+y)$$
