Sum & Difference Identities

Use online textbook to view videos & practice quizzes

http://www.mesacc.edu/~scotz47781/mat182/notes/Sum_Diff/Sum_Diff_Tan_Practice.pdf

https://math.libretexts.org/Bookshelves/Precalculus/Book%3A_Precalculus_(OpenStax)/07%3A_Trigonometric_Identities_and_Equations/7.2%3A_Sum_and_Difference_Identities

https://www.dummies.com/education/math/trigonometry/how-to-use-the-subtraction-identities-in-a-trig-problem/

https://www.youtube.com/watch?v=ZhvvkCa_60w

https://www.youtube.com/watch?v=hd2Tu0-Qb3k

https://www.youtube.com/watch?v=sU2pyMR8GZ4

https://www.onlinemathlearning.com/sum-identities.html