# parametric equations

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irreversible    2862
I feel kinda retarded asking this since I've actually taken math in uni several years ago, buuut... What I have is this: x4 - 5x2 + y4 - 5y2 + z4 - 5z2 + 11.8 = 0 I suppose the easiest way would be to convert this to polar form, which would give me:
  x4           x2
----- - ------------------ + ... = 1
-11.8   (sqrt(-11.8) / 5)2

Now, on my part I see several problems with this, the most important of which are: 1) I'm taking a square root of a negative number 2) I don't know how to go about extracting x, y and z from that I've mentioned before that I'm mathematically challenged, so I hope someone's willing to hand-walk me through this :) Cheers

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erissian    727
Parametric equations are great for describing systems that can be represented as paths. Consider if you could describe y as a function of t in your equation: you would still have a nontrivial number of solutions involving x and z. If you intend to break it down this way, you'll need at least two parametric variables.

I would keep that in mind, and try expressing this equation in spherical coordinates; the answer might just jump out then.

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grhodes_at_work    1385
irreversible, what is this for? You hint that you're no long in uni, but the problem looks academic and there's no information to suggest its really on topic. I'm troubled by your request for "hand-walk me through this". These forums are for game development, not general math, and though it is acceptable for there to be some academic discussions, I do not want people using these forums to just obtain answers.

The reply so far is appropriate, and I hope anyone else replying will provide hints not answers. Forum FAQ

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