Differential Equations

Differential equations are a type of equation whose solution is a function. This is in contrast to algebraic equations in which the solution is a number or collection of numbers.

Such equations occur naturally in engineering and the physical sciences because many of the phenomena that we one is interested in are described by functions. For example, when one is interested in temperature, say the temperature over the United States, one seeks the temperature at all points in the United States simultaneously. In mathematical language, one wants a formula or function that gives the temperature at any location.