*World of Mathematics*. ©2005-2006 Thomson Gale, a part of the Thomson Corporation. All rights reserved.

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## History of functions

The idea of a function was developed in the 17th century. During this time, Rene Descartes (1596-1650), in his book *Geometry* (1637), used the concept to describe many mathematical relationships. 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).

## Characteristics of functions

The idea of a function is very important in mathematics because it describes any situation in which one quantity depends on another. For example, the height of a person depends on his age. The **distance** an object travels in four hours depends on its speed. When such relationships exist, one **variable** is said to be a function of the other. Therefore, height is a function of age and distance is a function...

This section contains 1,249 words(approx. 5 pages at 300 words per page) |