Exercises 74 and 75 outline simple geometric derivations
Chapter 8, Problem 74(choose chapter or problem)
Exercises 74 and 75 outline simple geometric derivations of the formulas for sin(a b) and cos(a b) in the case in which a and b are acute angles, with a b 90. The exercises rely on the accompanying figures, which are constructed as follows. Begin, in Figure A, with GAD, HAG, and AH 1. Then, from H, draw perpendiculars to and to , as shown in Figure B. Finally, draw and FE BH FC AD. AD
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer