Sect 2b. Functions

CONCEPTS

  Function, correspondence, domain, codomain
  Image (of element and subset), preimage, range
  Graph of a function
  Properties: injective, surjective, bijective
  Composition, identity, inverse
  
SKILLS
  
  1. Identify concepts in a context
     E.g., tell the domain of a function
     E.g., tell the preimage of subset of the codomain
  2. Tell properties of functions
     E.g., whether a given function is injective or surjective
     E.g., compute images or pre-images of elements/subsets
  3. Determine functions given properties
     E.g., tell the composition of two functions
     E.g., tell whether a function has an inverse
     E.g., tell the inverse of a function
  
SOURCES

  *** Recommended ***   
  Tutorialspoint: Discrete Mathematics - Functions
  https://www.tutorialspoint.com/discrete_mathematics/discrete_mathematics_functions.htm

  *** Recommended ***
  Wikibooks: Algebra/Functions (many examples and pictures !!!)
  https://en.wikibooks.org/wiki/Algebra/Functions

  Youtube: Algebra Basics: What Are Functions? - Math Antics (very simple introduction)
  https://www.youtube.com/watch?v=52tpYl2tTqk

  *** Recommended ***
  Youtube: Discrete Math 1 by TheTrevTutor, videos 50-55
  https://www.youtube.com/playlist?list=PLDDGPdw7e6Ag1EIznZ-m-qXu4XX3A0cIz

  *** Recommended ***   
  Lerma, sect 2.2

  Hammack, chap 12 (!!! lots of examples and exercises !!!)