[Maxima-discuss] Resultant (bug)

[Karen K. <kar...@gm...>]

I wrote a simple function for calculating the discriminant:

discriminant(expr, var):= block([n], n: hipow(expand(expr), var),
resultant(expr, diff(expr, var), var)*(-1)^(n*(n-1)/2)/ratcoef(expr, var,
n))$

But, I spotted a bug in the resultant function:

Maxima 5.45:

(%i1) resultant(x^2/2-x+3, x-1, x)
(%o1) 5

Mathematica 12.3:

In[1]:=    Resultant[x^2/2-x+3, x-1, x]
Out[1]:= 5/2

Maple 2021:

resultant(x^2/2-x+3, x-1, x)
5/2