polylib::discrim
-- discriminant
of a polynomialpolylib::discrim
(p, x)
returns the
discriminant of the polynomial p
with respect to the
variable x
.
polylib::discrim(p,x)
x |
- | indeterminante |
p |
- | polynomial or polynomial expression |
polylib::discrim
returns an element of the coefficient
ring of p
. If the coefficient ring is Expr
or
IntMod(n)
, an expression is returned.
p
normal
is applied to the discriminant before returning it.We compute the discriminant of the general quadratic equation:
>> polylib::discrim(a*x^2 + b*x + c, x);
2 b - 4 a c
The discriminant of p
with respect to the variable
x
is defined as:
(-1)^(d * (d-1) / 2) * resultant(p, diff(p, x), x) / cwhere d is the degree and c is the leading coefficient of p.
discrim