Sum and Difference Formulas

Watch the lesson on mathtv.com. Click the play button in the lower left corner of the video lesson screen.  It requires Real Player, a free download. For an example to help with homework problems 65-76, watch problem 1 from this lesson. For an example to help with homework problems 99-104, watch problem 2 from the previous lesson.

Taft College provides this video that also requires Real Player.

Dr. Jacci White of St. Leo University recorded this video that also requires Real Player.