Functions
Basics of functions
Khan Academy Tutorial for the Basics of Functions
Domain and range of a function
Khan Academy Tutorial for Domain and Range
Difference quotient
YouTube Tutorial for the Difference Quotient
Transformations of functions
Khan Academy Tutorial for the Transformation of Functions
Basic functions:
, 
,
, 
YouTube Tutorial on Basic Functions
Piecewise-defined functions
YouTube Tutorial on Piecewise-Defined Functions
Function composition
Khan Academy Tutorial on Function Composition