Answer: The term "function" was introduced by Gottfried Wilhelm Leibniz (1646-1716) almost fifty years after the publication of Geometry. The idea of a function was further formalized by Leonhard Euler (pronounced "oiler" 1707-1783) who introduced the notation for a function, y = f(x).
Western Europe 1450-1750 the Roman Catholic church would no longer maintain its unity as a result of the Protestant Reformation ( new sects like Anclicanism,Lutheranism and Calvinism), Wars over religion (30yrs war) would see 1/3 of the population decimated, however reforms of the Catholic church (counter reformation)
The new Muslim states became centers of Islamic learning and reform.
