MATH 120 Lecture Notes - Lecture 7: Injective Function, Surjective Function, Lard

• School: Queen's University
• Department: Mathematics
• Course: MATH 120

Document Summary

Def . cardinality is the size of a set . " for finite sets . it is the number of distinct elements. Card is) : 5 are ways to denote the cardinality of s . functions and comparing sizes of sets : If a. bare sets f : a b , Def . f- is injective . or one-to-one if. Iy are distinct elements of a f- f- is surjective , or onto it. Hlbeb , faea for which flat :b: e. range (f) = b. is bijective if f- is both injective and surjective . Bijective functions are sometimes called one - to - one matchings , one - to - one correspondences . or bisections . Card (a) e card (b) if there is an injective function from a to b. B. at least one of the following is true : card / a) e card 113 , card 113) icardia)