A differential equation is an equation that defines the relationship between a function and its derivative. They are useful and essential tools in physics and engineering.History of the Differential from the 17th Century
History
In 1630s, the idea of finding a tangent to a curve was first explored in a calculus-like method by Gilles Persone de Roberval. In the same time period, Pierre de Fermat developed an understanding to the tangent of a curve using the concept of the infinitesimal, the idea that something could be infinitely divided into smaller and smaller segments. Sir Isaac Newton and Gottfried Wilhelm Leibniz further defined Fermat's method enabling its application.History of the Differential from the 17th Century
Differential Equations Theories
The Modeling Workshop: Differential Equations - Theory
University of Oxford: The Theory of Exponential Differential Equations
Stanford University: Theories Given by Differential Equations
Paul's Online Math Notes: Calculus and Differental Equations
