
5.1.31 extgcd
Syntax:
extgcd ( int_expression, int_expression )
extgcd ( bigint_expression, bigint_expression )
extgcd ( poly_expression, poly_expression )
Type:
 list of 3 objects of the same type as the type of the arguments
Purpose:
 computes extended gcd: the first element is the greatest common divisor
of the two arguments,
the second and third are factors such that if
list L=extgcd(a,b);
then L[1]=a*L[2]+b*L[3].
Note:
 Polynomials must be univariate (in the same variable) to apply
extgcd .
Example:
 extgcd(24,10);
==> [1]:
==> 2
==> [2]:
==> 2
==> [3]:
==> 5
ring r=0,(x,y),lp;
extgcd(x4x6,(x2+x5)*(x2+x3));
==> [1]:
==> x5+x4
==> [2]:
==> 1/2x2+1/2x+1/2
==> [3]:
==> 1/2

See
gcd;
int.
