### Home > CALC > Chapter 8 > Lesson 8.1.4 > Problem 8-42

8-42.

No calculator! Evaluate the integrals below.

Before integrating, make a choice:

You could factor outor you could let *U*= 9 − 2*x*.

Don't forget the absolute value!

Notice the symmetrical bounds.Is this function odd? If so, the area will be 0. If not, integrate.

Factor before integrating.

Recall that

.

*U*-substitution. Should*U*= sin*x*or*U*= cos*x*?