Maxima's unacceptable error



Jaime Robledo wrote:
> 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(%);

I get:

[x = .9999999999999992, x = 4.2734553247153e-5 %i + 1.99995756513013,
x = 1.99995756513013 - 4.2734553247153e-5 %i, x = 2.000084872600651,
x = 3.99994945773703, x = - 2.999999999941612, x = 4.000050539343674]

which looks like a root near 1, -3, two roots near 4 and 3 roots near 2. 
  The repeated roots usually makes the polynomial ill conditioned for a 
numerical root finder.

If you wanted exact roots, perhaps solve would produce the results 
you're looking for?

Ray