4. Condition for coefficients. Since one of the roots of sextic equation (1) is a
dependent root, one of the coefficients also will be a dependent coefficient, and it
will be determined by the remaining coefficients. To derive this relation (among the
coefficients) consider the equation (11), and substitute the values of b0 and c0 in
(11) using (15) and (19) respectively. We obtain the following expression containing
only the coefficients of (1).