5.4. Area of a Surface of Revolution http://www.ck12.org
Simplifying,
S=π
∫ 3
0
√
4 y+ 1 dy.
With the aid ofu−substitution, letu= 4 y+ 1 ,
S=π 4
∫ 13
1 u
1 / (^2) du
=π 6
[
( 13 )^3 /^2 − 1
]
=π 6 [ 46. 88 − 1 ]
≈ 24
Multimedia Links
For video presentations of finding the surface area of revolution(16.0), see Math Video Tutorials by James Sousa,
Surface Area of Revolution, Part 1 (9:47)
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/576
and Math Video Tutorials by James Sousa, Surface Area of Revolution, Part 2 (5:43).
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/577
Review Questions
In problems #1 - 3 find the area of the surface generated by revolving the curve about thex−axis.
1.y= 3 x, 0 ≤x≤ 1
2.y=√x, 1 ≤x≤ 9
3.y=
√
4 −x^2 ,− 1 ≤x≤ 1