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Author: Subject: Mathematical solution to two quadratics
International Hazard

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[*] posted on 16-5-2008 at 00:48

Some PDF articles relevant to quintic polynomial equations, their solubility (of special classes of them) and general insolubility, and Galois theory, from restricted Springerlink and Oxford journals, have been uploaded, and a link for downloading them is in the References section. Ask me privately for the link if you do not have access to the References section.
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Biochemicus Energeticus

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[*] posted on 19-5-2008 at 16:46

Ok, I've done some work on this:
With the hint from len1 I did the following:
(I'd appreciate someone checking, I'm utterly paranoid I made a mistake somewhere...pleeeease! :))
See attachment.

Substituting this into the cubic solution is ok, but now I have another problem: I need to find some regression software that can handle the third root! I couldn't find such a function in Sigmaplot - is anyone aware of graphing software that does advanced regression offering a third root function?

Please be aware that I fit real data (as Fobs) as in

Fobs = Fmin(Lo-[PL]) + Fmax([PL])

where Fobs are about 50 data points.
I therefore have to plug in the cubic solution into each [PL] in the eqn above, and by varying the KdPL (substituted as a) I get the best fitting curve (and the KdPL therefore is value I'm after)... Not sure if this is all making sense, but I did explain it in one of the attachments above.

Anyway, I'm now stuck with trying to find regression software that offers the third root... anyone?


competition.gif - 8kB

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