Double-angle or half-angle formula to simplify trig expressions

In these example problems, we are given a couple trigonometric (trig) expressions, we simplify by using either a double-angle formula or a half-angle formula. Then we simplify completely. Each part of this process is explained and written out step-by-step. This video contains examples that are from Algebra and Trigonometry, 1st ed, by Abramson, Belloit, Falduto, Gross, Lippman et al. It is an open-source textbook from OpenStax that you may download for free at https://openstax.org/details/books/al.... The text is licensed under the Creative Commons Attribution license. https://creativecommons.org/licenses/...