In calculus, an integral represents the area underneath a curve. The process in calculating the value of an integral is called integration. Outside of mathematics, ...

1675: Gottfried Leibniz writes the integral sign ∫ in an unpublished manuscript, introducing the calculus notation that’s still in use today. Leibniz was a German mathematician and philosopher ...

IN the second volume of his large treatise on the integral calculus, Mr. Edwards deals with multiple integrals, gamma functions, Dirichlet integrals, definite integrals in general, contour ...

Differential and Integral Calculus, with Applications. By Alfred George Greenhill Second Edition. (London: Macmillan and Co., 1891.) Nature - Differential and Integral Calculus, with Applications.