- #1
twoski
- 181
- 2
Homework Statement
Using disks or washers, find the volume of the solid obtained by rotating the region bounded by the curves y = x^2 and y = 4 about the line y = 4
The Attempt at a Solution
Since y=4 is parallel to the x-axis i assume i should be using the 'washer' method.
The points of intersection are x = 2, x = -2... But when i compute the volume i get the wrong answer.
[itex]V = \pi \int ^{2}_{-2} ( x^{4} - 8 )dx = 1/5 x^{5} - 8x | ^{2}_{-2}[/itex]
which results in pi * 64/5 which is apparently wrong...