5 Steps to a 5 AP Calculus AB 2019 - William Ma

MA 3972-MA-Book April 11, 2018 16:1

314 STEP 4. Review the Knowledge You Need to Score High

(a) Point of Intersection: Use the

[Intersection] function of the calculator

and obtain (0.517757, 0.868931).

Area =

∫ 0. 51775

0

(cosx−xex)dx

Enter

∫

(cos(x)−x∗e∧x, x,

0, 0. 51775 )and obtain 0.304261.

The area of the region is approximately

0.304.

(b) Step 1: Using the Washer Method:

Outer radius=cosx;

Inner radius=xex.

V=π

∫ 0. 51775

0

[

(cosx)^2 −(xex)^2

]

dx

Step 2: Enter π

∫ ((

cos(x)

)∧

2 −

(

x∗e∧(x)

)∧

2, x,0,0. 51775

)

and obtain 1.16678.

Thus, the volume of the solid

is approximately 1.167.