About This Lesson
Youtube videos by Julie Harland are organized at http://YourMathGal.com This video derives the identity for the tangent of the sum and difference of angles (or real numbers), and provides an example using the identity if you know the tangents of two angles, but not their sum. Aligned with Common Core State Standard: HSF-TF.9 . For more great math videos visit: www.youtube.com/user/videosbyjulieharland/videos
