OpenStax is a nonprofit based at Rice University, with a mission to improve student access to education. Their first openly licensed college textbook was published in 2012, and their library since scaled to more than 20 books for college and AP courses used by hundreds of thousands of students. OpenStax was founded in 1999 by Richard Baraniuk, an electrical engineering professor at Rice University. Originally named Connexions, OpenStax started as an Open Educational Resource (OER) repository where faculty around the world could publish, share, and remix educational materials. The online version of OpenStax books are always kept up-to-date and freely available. Instructors are welcome to submit errata suggestions via their book page on the OpenStax website for our subject matter experts to review.