He attended lectures on the numerical solution of equations and on definite integrals by M.
Discussions of the approximate calculation of definite integrals will be found in works on the infinitesimal calculus; see e.g.
In 1788 Legendre published a memoir on double integrals, and in 1809 one on definite integrals.
von Zeipel; the expression of definite integrals as determinants by A.
With definite integrals the limits of integration can also change.