Hi Ben.

That is certainly a messy equation when you try to rearrange for y. Personally I would change coordinates.

Changing to polar: , we get.

Maybe it's easier to work with from here.

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- September 11th 2012, 05:42 AM #1

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## xy(x^2 - y^2) = C

I wanted to plot for C=840 but realised I couldn't isolate either x or y

I went to quickmath.com and entered the general equation and got...

Solve Equation :: QuickMath.com - Automatic Math Solutions

This returned 3 equations for calculating y; 2 complex and 1 real.

I know that for (7, 3), (7, 5) and (8, 7) are co-ordinates on the curve.

I cannot get these results by plugging in C=840, x=7 to the equations returned by quickmath.com.

Am I doing something wrong?

Thx

Ben

- September 11th 2012, 05:59 AM #2

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- September 11th 2012, 08:36 AM #3

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- September 11th 2012, 11:20 AM #4

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- September 11th 2012, 12:04 PM #5

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- September 11th 2012, 12:42 PM #6

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