CK-12 Foundation
Ck 12: Algebra: Algebraic Functions
[Free Registration/Login may be required to access all resource tools.] In this lesson students determine if a given relation or graph is a function. Students watch a video tutorial, examine guided notes and attempt practice problems.
Texas A&M University
Wtamu Virtual Math Lab: Intermediate Algebra: Introduction to Functions
This introductory tutorial on functions offers important definitions, examples of functions, and practice exercises for you to complete and check.