Involving the fourth and no higher power of an unknown quantity or variable.
- ‘MacMahon then worked on invariants of binary quartic forms, following Cayley and Sylvester.’
- ‘Assessing the higher-degree models (unconstrained cubic model and quartic model) proved difficult computationally, with many replicates failing to converge to a likelihood maximum.’
- ‘Based on Tartaglia's formula, Cardan and Ferrari, his assistant, made remarkable progress finding proofs of all cases of the cubic and, even more impressively, solving the quartic equation.’
- ‘Le Paige studied the generation of plane cubic and quartic curves, developing further Chasles's work on plane algebraic curves and Steiner's results on the intersection of two projective pencils.’
- ‘Orthogonal contrasts were used to test linear, quadratic, cubic, and quartic effects of proportions of SFGS in diet substrates on rate of fermentation.’
A quartic equation, function, curve, or surface.
- ‘Ferrari had solved the quartic by radicals in 1540 and so 250 years had passed without anyone being able to solve the quintic by radicals despite the attempts of many mathematicians.’
- ‘Pacioli does not discuss cubic equations but does discuss quartics.’
- ‘Ramanujan was shown how to solve cubic equations in 1902 and he went on to find his own method to solve the quartic.’
- ‘Cardan published both the solution to the cubic and Ferrari's solution to the quartic in Ars Magna convinced that he could break his oath since Tartaglia was not the first to solve the cubic.’
- ‘After subsequent work failed to solve equations of higher degree, Lagrange undertook an analysis in 1770 to explain why the methods for cubics and quartics are successful.’
Mid 19th century: from Latin quartus fourth + -ic.