bezout

Arguments

p1, p2

two real polynomials or two integer scalars (type equal to 8)

Description

[thegcd,U]=bezout(p1,p2) computes GCD thegcd of p1 and p2 and in addition a (2x2) unimodular matrix U such that:

[p1,p2]*U = [thegcd,0]

The lcm of p1 and p2 is given by:

p1*U(1,2) (or -p2*U(2,2))

Examples

// polynomial case
x=poly(0,'x');
p1=(x+1)*(x-3)^5;p2=(x-2)*(x-3)^3;
[thegcd,U]=bezout(p1,p2)
det(U)
clean([p1,p2]*U)
thelcm=p1*U(1,2)
lcm([p1,p2])

// integer case
i1=int32(2*3^5); i2=int32(2^3*3^2);
[thegcd,U]=bezout(i1,i2)
V=int32([2^2*3^5, 2^3*3^2,2^2*3^4*5]);
[thegcd,U]=gcd(V)
V*U
lcm(V)

See Also

• poly — polynomial definition
• roots — roots of polynomials
• simp — rational simplification
• clean — cleans matrices (round to zero small entries)
• lcm — least common multiple

Authors

S. Steer INRIA