Bombelli, Raffaele (c. 1526–1573)

Italian mathematician. An engineer in the service of the bishop of Melfi, he published his major work, his three-volume L'algebra/Algebra, in 1572. This contained important advances in the solution of equations, and in the development of an adequate algebraic symbolism.

The analysis of the cubic equation proposed by Tartaglia had led to a number of cases involving roots of negative numbers. Unsure of how to deal with such problems, Renaissance mathematicians had classified them as irreducible cases and ignored them. Bombelli, however, made the first significant advance in the handling of such problems.

In the field of symbolism he took the step of representing unknown quantities and exponents by special symbols. Though other systems came to be preferred, Bombelli had nonetheless shown the need for such expressions.