Jo S.

asked • 12/04/20

The Unit Circle and Trignomoetric Functions

Use the Sum Formula for Cosine to derive the following identity for the average rate of change of the cosine function:


cos (x + h) − cos x /h = cos x (cos h − 1)/h − sin x (sin h)/h


Note: You will learn in Calculus 1 that limh→0(cos h−1)/h = 0 and that limh→0 sin h/h = 1. It follows that the instantaneous rate of change of cos x is − sin x.

1 Expert Answer

By:

Josie S. answered • 12/04/20

Tutor
5 (1)

Experienced Teacher Specialized in High School Math

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.