Proof of d dx 1cos x2 _ _sin x Use the definition of the
Chapter 3, Problem 75(choose chapter or problem)
Proof of d dx 1cos x2 _ _sin x Use the definition of the derivative and the trigonometric identity cos 1x + h2 = cos x cos h - sin x sin h to prove that d dx 1cos x2 = -sin x.
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