The quartic formula is a name sometimes given to one of the related explicit formulas for the four roots ,
...,
of an arbitrary quartic equation with real coefficients
Then one of its most common forms of the quartic formula is given by
(3)
(4)
(5)
(6)
where
(7)
(8)
(9)
(Abramowitz and Stegun 1972, p. 17; Beyer 1987a, p. 12).
Ferrari was the first to develop an algebraic technique for solving the general quartic, which was stolen and published in Cardano's Ars Magna in 1545 (Boyer and Merzbach
1991, p. 283).