# E

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## E

, letter of the alphabet
E, fifth letter of the alphabet. It is a usual symbol for a mid-front vowel, such as ĕ in the English step. A mid-front vowel was represented by Greek epsilon [Gr.,=e without the aspirate], to which E corresponds in form and place (see also H). English ē is pronounced as a diphthong of ĭ and y. In musical notation E represents a note in the scale.

## e

, in mathematics
e, in mathematics, irrational number occurring widely in mathematics and science, approximately equal to the value 2.71828; it is the base of natural, or Naperian, logarithms. The number e is defined as the limit of the expression (1+1/n)n as n becomes infinitely large, or In 1873 the French mathematician C. Hermite proved that e was transcendental, i.e., not a root of any algebraic equation; this proof constituted a great contribution to the growth of mathematics. The number e is also known as Euler's number, for Leonhard Euler, who discovered the famous formula eiπ=−1, where i= √−1, thus expressing the relationship between the numbers e, i, and π. The exponential function ex, often written exp(x), occurs in various applications ranging from statistics to nuclear physics.

### Bibliography

See study by E. Maor (1994).

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

## E

(in Russian, Napier number), the limit of the expression [1 + (1/n)]n as n increases without bound:

It is the base of the natural system of logarithms. The number e is a transcendental number; this fact was first proved in 1873 by C. Hermite. Naming the number e after J. Napier is not entirely valid. (See.)

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

## e

(mathematics)
The base of the natural logarithms; the number defined by the equation approximately equal to 2.71828.

## E

(electricity)
(science and technology)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

## class A, B, C, D, E, F

A classification applied to fire doors, fire windows, roof coverings, interior finishes, places of assembly, etc., to indicate gradations of fire safety. See fire-endurance, fire-door rating.

## E

Symbol for “90° elbow.”
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

## E

(1)
An extension of C++ with database types and persistent objects. E is a powerful and flexible procedural programming language. It is used in the Exodus database system.

ftp://ftp.cs.wisc.edu/exodus/E/.

["Persistence in the E Language: Issues and Implementation", J.E. Richardson et al, Soft Prac & Exp 19(12):1115-1150 (Dec 1989)].

## E

(language)
A procedural language by Wouter van Oortmerssen with semantics similar to C. E features lists, low-level polymorphism, exception handling, quoted expressions, pattern matching and object inheritance. Amiga E is a version for the Amiga.