Solved: (Cosine law) Deduce the law of cosines by using
Chapter 9, Problem 9.1.70(choose chapter or problem)
(Cosine law) Deduce the law of cosines by using vectors a, b, and a - b.
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