Free educational resources can be hard to come by, especially finding them in detailed and easy-to-understand formats. However, the website cK-12 has free textbooks for a variety of subjects and grade levels, all of which are available online, can be downloaded on your Kindle or iPad, or viewed as a PDF.
- Right Triangles and Introduction to Trigonometry
- Inverse Trigonometric Functions
- Polar System
- Graphing Trigonometric Functions
- Trigonometric Identities and Equations
- Triangles and Vectors
Furthermore, there is a selection of seven FlexBooks that cover Mathematics – Trigonometry, the details of which can be found in the LIST. Again, these textbooks can be viewed online, viewed as a PDF, or downloaded onto your Kindle or iPad. And it’s all free!