This book is derived from Precalculus, 3rd Corrected Edition by Carl Stitz and Jeff Zeager, available under a Creative Commons Attribution-NonCommercial-ShareAlike license. Chapters 7-9 and Sections 4.3 and 11.4-11.10 -- those not needed for Introduction to Functions and Precalculus courses at Fitchburg State University -- have been removed. The complete, original text is freely available at http://www.stitz-zeager.com/.