Areas, Volumes, and Arc Lengths 295
12.7 Practice Problems
Part A The use of a calculator is not
allowed.
- LetF(x)=
∫x
0
f(t)dt, where the graph of
f is given in Figure 12.7-1.
01234
4
–4
5
f
y
x
Figure 12.7-1
(a) EvaluateF(0),F(3), andF(5).
(b) On what interval(s) isFdecreasing?
(c) At what value oftdoesFhave a
maximum value?
(d) On what interval isFconcave up?
- Find the area of the region(s) enclosed by
the curvef(x)=x^3 , thex-axis, and the lines
x=−1 andx=2. - Find the area of the region(s) enclosed by
the curvey=
∣∣
2 x− 6
∣∣
, thex-axis, and the
linesx=0 andx=4.
- Find the approximate area under the curve
f(x)=
1
x
fromx=1tox=5, using four
right-endpoint rectangles of equal lengths.
- Find the approximate area under the curve
y=x^2 +1 fromx=0tox=3, using the
Trapezoidal Rule withn=3.
6.Find the area of the region bounded by the
graphsy=
√
x,y=−x, andx=4.
7.Find the area of the region bounded by the
curvesx=y^2 andx=4.
8.Find the area of the region bounded by the
graphs of all four equations:
f(x)=sin
(
x
2
)
;x-axis; and the lines,
x=
π
2
andx=π.
9.Find the volume of the solid obtained by
revolving about thex-axis, the region
bounded by the graphs ofy=x^2 +4, the
x-axis, they-axis, and the linesx=3.
- The area under the curvey=
1
x
fromx= 1
tox=kis 1. Find the value ofk.
- Find the volume of the solid obtained by
revolving about they-axis the region
bounded byx=y^2 +1,x=0,y=−1, and
y=1. - LetRbe the region enclosed by the graph
y= 3 x, thex-axis, and the linex=4. The
linex=adivides regionRinto two regions
such that when the regions are revolved
about thex-axis, the resulting solids have
equal volume. Finda.
Part B Calculators are allowed. - Find the volume of the solid obtained by
revolving about thex-axis the region
bounded by the graphs of f(x)=x^3 and
g(x)=x^2. - The base of a solid is a region bounded by
the circlex^2 +y^2 =4. The cross sections of
the solid perpendicular to thex-axis are
equilateral triangles. Find the volume of the
solid. - Find the volume of the solid obtained by
revolving about they-axis, the region
bounded by the curvesx=y^2 , andy=x−2.