Noun
the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
Source: WordNetBecause of this, the Principia has been called "a book dense with the theory and application of the infinitesimal calculus" in modern times Clifford Truesdell, Essays in the History of Mechanics (Berlin, 1968), at p.99. Source: Internet
Following the work of Weierstrass, it eventually became common to base calculus on limits instead of infinitesimal quantities, though the subject is still occasionally called "infinitesimal calculus". Source: Internet
Given the name infinitesimal calculus, it allowed for precise analysis of functions within continuous domains. Source: Internet
His development of infinitesimal calculus opened up new applications of the methods of mathematics to science. Source: Internet
Historical Much of the earliest development of the infinitesimal calculus by Newton and Leibniz was formulated using expressions such as infinitesimal number and vanishing quantity. Source: Internet
It opens with a mathematical exposition of "the method of first and last ratios", citation a geometrical form of infinitesimal calculus. Source: Internet