Use the difference formula for sine

In this math example, we use a difference formula for sine to simplify a trig expression. To do so, we first identify what values will be filled in for each part of the formula (alpha and beta). They are filled in and we simplify by evaluating sine and cosine at the given angle.
sin(u-pi/2)
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 openstax.org/d.... The text is licensed under the Creative Commons Attribution license. creativecommon...