Bernoulli was a Swiss mathematician who, with his brother Johann, pioneered German mathematician Gottfried Leibniz’s calculus. The first to use the word “integral” in solving Leibniz’s problem of the isochronous curve, Jakob used calculus to study the forms of many curves arising in practical situations. In 1713, he wrote Ars Conjectandi, or The Art of Conjecture, an important treatise on the theory of probability that contained the Bernoulli numbers, which are what?
Source: The Free Dictionary