Prove the following identities. (These two identities,
Chapter 6, Problem 80(choose chapter or problem)
Prove the following identities. (These two identities, along with are known as the Pythagorean identities. They will be discussed in Chapter 8.)
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