I need a cartesian formula for the parametric equations: x=t^2+1 y=t^2-t
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Originally Posted by anon12345 I need a cartesian formula for the parametric equations: x=t^2+1 .... (1) y=t^2-t .... (2) From (1): $\displaystyle t = \pm \sqrt{x - 1}$ From (2): $\displaystyle 0 = t^2 - t - y \Rightarrow t = \frac{1 \pm \sqrt{1 - 4y}}{2}$ using the quadratic formula. Therefore $\displaystyle \pm \sqrt{x - 1} = \frac{1 \pm \sqrt{1 - 4y}}{2}$ etc.
Last edited by mr fantastic; May 5th 2008 at 09:40 PM. Reason: Misread y = t^2 - t as y = t^2 - 1
I've already determined that y=x-2t from subtracting the 2 equations however that is not a cartesian representation because of the t.
Originally Posted by anon12345 I've already determined that y=x-2t from subtracting the 2 equations however that is not a cartesian representation because of the t. Sorry, I misread the question. I've edited my reply. Please take another look.
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