In mathematics, a continuous function (continuity) is a function for which, intuitively, small changes in the input result in small changes in the output. Otherwise, a function is said to be "discontinuous." A continuous function with a continuous inverse function is called "bicontinuous."

Continuity of functions is one of the core concepts of topology, which is treated in full generality below. The introductory portion of this article focuses on the special case where the inputs and outputs of functions are real numbers. In addition, this article discusses the definition for the more general case of functions between two metric spaces. In order theory, especially in domain theory, one considers a notion of continuity known as Scott continuity?. Other forms of continuity do exist but they are not discussed in this article.

As an example, consider the function h(t), which describes the height of a growing flower at time t. This function is continuous. In fact, a dictum of classical physics states that in nature everything is continuous. By contrast, if M(t) denotes the amount of money in a bank account at time t, then the function jumps whenever money is deposited or withdrawn, so the function M(t) is discontinuous. (However, if one assumes a discrete set as the domain of function M, for instance the set of points of time at 4:00 PM on business days, then M becomes continuous function, as every function whose domain is a discrete subset of reals is.) Wikipedia - Continuity or Continuous Function (external link)

See Also

9.11 - Love or Sympathy is Perfect Continuity
Continuous Motion

Created by Dale Pond. Last Modification: Thursday 07 of July, 2011 04:33:09 MDT by Dale Pond. (Version 1)
The original document is available at