I have the following Mathematica code:
a = x^3 + x^2 + 4 x + 4;
b = 3 x^4 + x^2 + 1;
d = PolynomialGCD[a, b, x, Modulus -> 5];
Print["d=", d]
{d1, {s, t}} = PolynomialExtendedGCD[a, b, x, Modulus -> 5];
Print["d1=", d1]
which gives the following output:
d=1
d1=4+x^2
The correct answer is $1$ indeed. So is PolynomialExtendedGCD working incorrect?
P.S. I am using Mathematica 11.0.0.0 on Ubuntu.
