On November 11, 1675, German mathematician and polymath Gottfried Wilhelm Leibniz demonstrates integral calculus for the first time to find the area under the graph of y = ƒ(x).
J. Heiberg (Eds.) Bibliotheca scriptorum graecorum et romanorum teubneriana (BT) In Aedibvs B.G. Tevbneri MCMLXXII, Stvtgardiae, Editio stereotypa editionis anni MCMX edition, (1972)