Browse Definitions :

approximate equality

Approximate equality is a concept used primarily in physics and engineering, and also occasionally in mathematics. Two quantities are approximately equal when they are close enough in value so the difference is inconsequential in practical terms. Approximate equality is symbolized by a squiggly equal sign ( ).

As an example of how approximate equality can be used in mathematics, consider the positive square root of 2 (or 2 1/2 ). This is an irrational number ; when written in decimal form, it is nonterminating and nonrepeating. Expressed to four significant digits, 2 1/2 1.414. It is possible to express it to many more significant digits, but the result will always be an approximation. Thus, to 10 significant digits, 2 1/2 1.414213562, and to 20 significant digits, 2 1/2 1.4142135623730950488. An example of an approximate equation using variables is x + y z .

In experimental physics and engineering, approximate equality is the rule, because measurements of physical quantities and phenomena are seldom exact. We might say, for example, that an incandescent lamp consumes a power P of approximately 60 watt s (60 W); then we can write P 60 W. Or we might say that the speed S of a computer-file download is approximately 38.3 kilobit s per second (kbits/sec); we would then write S 38.3 kbits/sec.

In many cases, the ordinary equality symbol (=) is used in situations where, to be rigorous, the approximate equality sign ought to be used. This is done for two reasons: first, most fonts do not include an approximate equality symbol; and secondly, many people do not know what the approximate equality symbol means.

Also see Mathematical Symbols .

This was last updated in September 2005
  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

  • enterprise document management (EDM)

    Enterprise document management (EDM) is a strategy for overseeing an organization's paper and electronic documents so they can be...

  • IPsec (Internet Protocol Security)

    IPsec (Internet Protocol Security) is a suite of protocols and algorithms for securing data transmitted over the internet or any ...

  • principle of least privilege (POLP)

    The principle of least privilege (POLP) is a concept in computer security that limits users' access rights to only what are ...

  • biometric authentication

    Biometric authentication is a security process that relies on the unique biological characteristics of individuals to verify they...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

  • cloud testing

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...