[Maxima] Maxima's unacceptable error

Mario Rodriguez biomates at telefonica.net
Thu Jan 3 10:50:59 CST 2008

Jaime Robledo escribió:
> In Maxima, the polynomial (x-4)^2*(x-2)^3*(x-1)*(x+3) has two complex roots
> and only one integer root. Try it yourself:
> %i1 (x-4)^2*(x-2)^3*(x-1)*(x+3);
> %i2 allroots(%);

allroots is a numerical solver and roots are approximate. See that 
imaginary parts are near zero. I don't know if it is possible to control 
its accuracy; maybe someone in the list can tell us something about this.

According to documentation, you can try allroots(%i*p) and compare results.

A symbolic solver gives better results:

(%i6) (x-4)^2*(x-2)^3*(x-1)*(x+3)$
(%i7) solve(%);
(%o7)                   [x = - 3, x = 1, x = 2, x = 4]


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Thanks a lot for your interest in Maxima.

Mario Rodriguez Riotorto

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