computeDiscriminant
Provides the discriminant of the quartic equation from the supplied coefficients.
Return
The value of the discriminant.
Parameters
a
The coefficient of the 4th order monomial.
b
The coefficient of the 3rd order monomial.
c
The coefficient of the 2nd order monomial.
d
The coefficient of the 1st order monomial.
e
The coefficient of the 0th order monomial.