From Pat’s Blog: http://pballew.blogspot.ca/2010/08/whoddd.html
When I found the whole article, it turned out to be an interesting historical, mathematical journal entry, “The Lost Calculus (1637-1670), Tangency and Optimization without Limits”, by Jeff Suzuki in the MAA Mathematics Magazine, Dec, 2005. In A History of Mathematics, by Cajori, we find that Hudde was the first to use three variables in analytic geometry. The article by Suzuki would seem to be a wonderful historical read for calculus teachers who, like me, never heard of Hudde’s rule.
René Descartes (1596-1650), Blaise Pascal (1623-1662) triangle, Pierre de Fermat (1601-1665), Johannes Hudde (1628-1704), Gottfried Wilhelm von Leibniz (1647-1716), Isaac Newton (1643-1727) fluxions & fluents