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# Parametric equations

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1. Parametric equation help,

X = t^2 + t

Y = T^2 - T

I need to rearrange to get a cartesian equation, but i dont know how to rearrange it when they is a t squred and normal T, I know im being a bit stupid and missing a trick here..
2. (Original post by SunDun111)
Parametric equation help,

X = t^2 + t

Y = T^2 - T

I need to rearrange to get a cartesian equation, but i dont know how to rearrange it when they is a t squred and normal T, I know im being a bit stupid and missing a trick here..
Subtract one from the other to get rid of the t^2, then sub back into either.

OR

having subtracted one from t'other to get t, add the two to get t^2, and sub the value for t into that.
3. (Original post by SunDun111)
Parametric equation help,

X = t^2 + t

Y = T^2 - T

I need to rearrange to get a cartesian equation, but i dont know how to rearrange it when they is a t squred and normal T, I know im being a bit stupid and missing a trick here..
Spoiler:
Show
Note that if you add both equations you get:

and if you subtract both equations you get .

So: .

Edit: too slow.
4. I would do it a slightly different way.
and so if we divide
you get the cartesian equation to be

or
.

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