### Home > PC3 > Chapter 8 > Lesson 8.3.4 > Problem 8-144

8-144.

Let

*f*(*x*) = sin(*x*). Homework Help ✎Calculate the average rate of change from

*x*=to *x*=. Write an expression for the average rate of change from

*x*=to *x*=+ *h*.Use the fact that sin(

*A*+*B*) = sin(*A*)cos(*B*) + cos(*A*)sin(*B*) to show that the expression you wrote in part (b) can be rewritten as. Use the fact that

and to evaluate .

Substitute values for the trigonometric expressions and simplify.