Notice that (14) is a cubic equation in p1 with real coefficients, and when solved over the
real field it provides at least one real root. Once p1 is known p is evaluated from (13), and
then, b0 and c0 are found out from (9) and (10) respectively. Having determined all the
unknowns, we are in a position to represent the given quartic equation (1) in the form of
(2), whose factors are quadratic polynomials as given in (3). Equating each of these
factors to zero, and solving the resulting quadratic equations, we get all the four roots of
given quartic (1) as shown below.