Re: TI86 equation solving


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Re: TI86 equation solving



RWW Taylor wrote:

> JLC <nsx3000@BIGFOOT.COM> writes:
>
> > How do I solve a quadratic equation in TI86? (ex. X^2+X-2=0)
>
> Use the quadratic formula -- 99% of the time this will be the most satisfactory
> method.  And it's a good idea to enter it directly, too, to watch what is
> happening.  Something like this:
>
> 1 -> a : 1 -> b : -2 -> c
>
> b*b-4a*c -> D
>
> (-b + sqrt(D)) / (2a) -> x1
> (-b - sqrt(D)) / (2a) -> x2  (recall the Entry to save re-typing)

It's worth noting that occasionally the coefficients make this formula
computationally unstable (if -b + sqrt(D) <10^-12?) in which case the alternative
quadratic formula: -2c/(b + sqrt(D)) may be preferable.  It's something like this -
you may want to check since I'm somewhat hurried at the moment.

-Geoffh

ps  Why *does* Mongoose start with a "p?"


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