
resultant - resultant of two polynomials

Calling sequence:
resultant(poly_1, poly_2 [ , expr ])
resultant(expr_1, expr_2 [ , indets ]  [ , expr ])
indets  ---> [ expr_3 ...]

Parameter:
poly_1, poly_2               --   polynomials
expr, expr_1, expr_2, expr_3 --   expressions

Overloading:

1,2

Summary:

resultant returns the resultant of the poynomials poly_1 and poly_2 with
respect to the variable expr.

If no variable is given then the resultant is determined with respect to the
main variable of the polynomials (this is the first element in the list of
variables in the polynomials).

The first two arguments may be either polynomials or expressionsand optionally
a listof variables. If the arguments are expressions then these are converted

into polynomials (see function poly). resultant returns FAIL if the expressions
cannot be converted. Both polynomials must be of the same type, i.e. their
variables and coefficient rings must be identically.

If the arguments are expressions, then the result is an expression.  If the
arguments are univariate polynomials, then the result is an element of the
coefficient ring.  If the arguments are multivariate polynomials, then the
result is a polynomial not containing the variable expr.

>>  resultant(a*x+b, c*x+d, x);

      a*d - b*c

>>  resultant(poly(x^2 - 1), poly(x + 1));

      0

See also:  gcd, poly

