function value = r8poly2_discriminant ( a, b, c )

%*****************************************************************************80
%
%% r8poly2_discriminant() returns the discriminant of a quadratic polynomial.
%
%  Discussion:
%
%    The polynomial has the form:
%
%      A * X^2 + B * X + C = 0 
%
%    If the discriminant is zero, then the polynomial has a multiple root.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    14 July 2019
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real A, B, C, the coefficients of the polynomial.
%
%  Output:
%
%    real VALUE, the discriminant.
%
  value = b * b - 4.0 * a * c;

  return
end
