- Integral symbol
The Unicode|∫
symbol is used to denote theintegral inmathematics . The notation was introduced by the German mathematicianGottfried Wilhelm von Leibniz towards the end of the 17th century. The symbol was based on the Unicode|ſ (long s ) character, and was chosen because the integral is a limit of sums. Seelong s for more details on the history of Unicode|ſ.The Unicode|∫ symbol is U+222B in
Unicode ,int
inLaTeX . InHTML , it is written as∫
(hexadecimal),∫
(decimal) and∫
(named entity).The original
IBM PC code page 437 character set included a couple of characters Unicode|⌠ and Unicode|⌡ (codes 244 and 245, respectively) to build the integral symbol. These were deprecated in subsequentMS-DOS code page s, but they still remain inUnicode (U+2320 and U+2321, respectively) for compatibility.The Unicode|∫ symbol is very similar to, but not to be confused with, the (IPA|ʃ) symbol (called esh).
Related symbols are Unicode|∬ (
double integral , U+222C), Unicode|∭ (triple integral , U+222D), Unicode|∮ (contour integral , U+222E), Unicode|∯ (surface integral , U+222F), and Unicode|∰ (volume integral , U+2230).References
*cite book | last = Stewart | first = James | title = Single Variable Calculus: Early Transcendentals | accessdate = 2006-06-26 | edition = 5th edition | year = 2003 | publisher = Brooks/Cole | location = Belmont, CA | id = ISBN 0-534-39330-6 | pages = 381 | chapter = Integrals
External links
* http://www.fileformat.info/info/unicode/char/222b/index.htm
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