ane o the twa main operations in calculus
Integration is an important concept in mathematics an, thegither wi its inverse, differentiation, is ane o the twa main operations in calculus. Gien a function f o a real variable x an an interval [a, b] o the real line, the definite integral
is defined informally tae be the signed aurie o the region in the xy-plane boondit bi the graph o f, the x-axis, andthe vertical lines x = a an x = b, such that aurie abuin the x-axis adds tae the tot, an that ablo the x-axis subtracts frae the tot. Lebesgue integration is aan impoitint concept, reprisainten ane geniralizaition of this concept.