Math 101T - Trigonometry

Purpose: to help other instructors teaching the same course

Common Course ID:  MATH 101T
CSU Instructor Open Textbook Adoption Portrait

Abstract: This open textbook is being utilized in a trigonometry course for undergraduate students by Barry Chin at Cal Poly Humboldt. The open textbook provides a solutions manual and basic PowerPoint files. The main motivation to adopt an open textbook was to be accessible to students. Most student access the open textbook in online format. 

Course Title and Number - Math 101T - Trigonometry
Brief Description of course highlights:  Trigonometric functions, their graphs, inverses and applications, radian measure, solving triangles, trigonometric identities and equations, laws of sines and cosines, polar coordinates, vectors. https://catalog.humboldt.edu/preview_course_nopop.php?catoid=10&coid=56987  

Student population: The student population is primarily science majors, with a few exceptions, and mostly consists of freshmen and sophomores. Many students have tested in, and some have taken the course in high school, though retention of material varies.

Learning or student outcomes: 
- Convert between degree and radian measure of an angle
- Use right triangles to evaluate the trigonometric functions of an acute angle
- Solve applied problems involving right triangles
- Use the unit circle to evaluate trigonometric functions
- Find the value of the trigonometric functions of an angle given the value of one trig function and the quadrant of the angle
- Correctly evaluate inverse trigonometric functions and draw their graphs
- Use radian measure to solve applied problems
- Graph the trigonometric (and sinusoidal) functions over one or several periods
- Use sum and difference formulas to evaluate or simplify trigonometric expressions
- Use algebraic techniques to simplify trigonometric expressions
- Establish/verify trigonometric identities
- Solve equations involving trigonometric functions
- Solve oblique triangles using the Law of Sines and Law of Cosines
- Solve applied problems using the Law of Sines and Law of Cosines
- Convert between polar and rectangular coordinates
- Evaluate linear combinations of vectors and find the resultant vector’s angle and magnitude
- Compute dot products of vectors
- Find angles between vectors 

Syllabus and/or Sample assignment from the course or the adoption: The textbook is integrated into my Canvas page to clearly communicate each section’s expectations.

Textbook/OER/Lowcost Title: OpenStax Precalculus 2e 
Brief Description:  A free textbook that covers trigonometry well. There is a clear, modular structure with learning objectives, worked examples, practice problems, and conceptual, graphical, and application-based exercises. Each chapter concludes with a review and practice test.
Please provide a link to the resource  https://openstax.org/details/books/precalculus-2e , also available in Spanish.

Authors:  Jay Abramson

Student access:  Students can an access through links in Canvas and the course syllabus. At least some have bought the paper copy. Most students use the Canvas link or the PDF for convenience.

Supplemental resources:  A Spanish version is available. Instructor resources include integration files for Canvas, a complete solutions manual, customizable PowerPoint slides, and editable Word (.doc) files for adapting materials to specific course needs.

Provide the cost savings from that of a traditional textbook.  ~$40.00

License*: Creative Commons Attribution 4.0 International License.

OER/Low Cost Adoption Process
Provide an explanation or what motivated you to use this textbook or OER/Low Cost option.  
The text is good because it promotes access and helps eliminates financial barriers for students. Even for those who can afford traditional texts, the OpenStax version is more convenient and flexible. Students can access it anywhere, anytime, even if they forget their physical book.

How did you find and select the open textbook for this course?  
I have used their materials for other classes.

Sharing Best Practices: 
Using free resources ensures all students have immediate access to materials. No delays or missing books, which has greatly improved preparedness and consistency. For new faculty, I recommend starting with well-supported options like OpenStax. I wish I’d known earlier how much this improves the start of the semester.

Describe any key challenges you experienced, how they were resolved  and lessons learned.  
I wish I had known earlier that students could order just the second half of the book. It’s more affordable, lighter, and better suited for a trig-only course.

Instructor Name - Barry Chin
I am a math lecturer at the Cal Poly Humboldt.
Please provide a link to your university page.
https://www.humboldt.edu/mathematics/barry-chin

Please describe the courses/course numbers that you teach.  
I teach Trigonometry and Math for Liberal Arts.

Describe your teaching philosophy and any research interests related to your discipline or teaching.  
My teaching philosophy is student-centered, emphasizing active learning, inclusion, and growth through curiosity and collaboration. I aim to create a supportive classroom environment where students feel comfortable engaging, asking questions, and learning from mistakes. I focus on helping students build both conceptual understanding and confidence in applying mathematical thinking to real-world problems