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;e13;none;1;e13;;;block;;;;no;1;4224n;90919n;;;;;eq13;comptd;;center;stack;;;;;CE5In 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 e i π = - 1, where i = - 1art/square-root-of-negative-1.gif the square root of negative 1, thus expressing the relationship between the numbers e, i, and π. The exponential function e x , often written exp( x ), occurs in various applications ranging from statistics to nuclear physics.

See study by E. Maor (1994).

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