# Inverse function

A function f an its inverse f −1. Acause f maps a tae 3, the inverse f −1 maps 3 back tae a.

In mathematics, an inverse function (or anti-function[1]) is a function that "reverses" anither function: gin the function f applee'd tae an inpit x gies a result o y, then appleein its inverse function g tae y gies the result x, an vice versa, i.e., f(x) = y gin an anerly gin g(y) = x.[2][3]

## References

1. Hall, Arthur Graham; Frink, Fred Goodrich (January 1909). "Chapter II. The Acute Angle [14] Inverse trigonometric functions". Written at Ann Arbor, Michigan, USA. Trigonometry. Part I: Plane Trigonometry. New York, USA: Henry Holt and Company / Norwood Press / J. S. Cushing Co. - Berwick & Smith Co., Norwood, Massachusetts, USA. p. 15. Retrieved 2017-08-12. […] α = arcsin m: It is frequently read "arc-sine m" or "anti-sine m," since two mutually inverse functions are said each to be the anti-function of the other. […] A similar symbolic relation holds for the other trigonometric functions. […] This notation is universally used in Europe and is fast gaining ground in this country. A less desirable symbol, α = sin-1m, is still found in English and American texts. The notation α = inv sin m is perhaps better still on account of its general applicability. […] Cite uses deprecated parameter |dead-url= (help)
2. Keisler, Howard Jerome. "Differentiation" (PDF). Retrieved 2015-01-24. §2.4
3. Scheinerman, Edward R. (2013). Mathematics: A Discrete Introduction. Brooks/Cole. p. 173. ISBN 978-0840049421.