Editing Linear function (section)

{{short description|Linear map or polynomial function of degree one}}
{{for|the use of the term in calculus|Linear function (calculus)}}
In [[mathematics]], the term '''linear function''' refers to two distinct but related notions:<ref>"The term ''linear function'' means a linear form in some textbooks and an affine function in others." Vaserstein 2006, p. 50-1</ref>
* In [[calculus]] and related areas, a linear function is a [[function (mathematics)|function]] whose [[graph of a function|graph]] is a [[straight line]], that is, a [[polynomial function]] of [[polynomial degree|degree]] zero or one.<ref>Stewart 2012, p. 23</ref> For distinguishing such a linear function from the other concept, the term ''[[affine function]]'' is often used.<ref>{{cite book|author=A. Kurosh|title=Higher Algebra|year=1975|publisher=Mir Publishers|page=214}}</ref>
* In [[linear algebra]], [[mathematical analysis]],<ref>{{cite book|author=T. M. Apostol|title=Mathematical Analysis|year=1981|publisher=Addison-Wesley|page=345}}</ref> and [[functional analysis]], a linear function is a [[linear map]].<ref>Shores 2007, p. 71</ref>