- #1
Caldus
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I am having a lot of trouble with these last 3 problems out of 10 that I have done relating to volumes. I have tried just about every method for each of these and I am just not getting the right answer (according to this online math program I am using).
2. Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis:
y = x^2, y = 1; about y = 2.
The resulting solid for me looks like a volcano. So I used the Shell method like so:
A(x) = length * width
A(x) = 2*pi*(x)*x^2 = 2*pi*x^3
V = integral b/w 0 and 1 of A(x) ...
Not getting the right answer here either...
3. A ball of radius 11 has a round hole of radius 4 drilled through its center. Find the volume of the resulting solid.
I tried using vertical washers like so:
A(x) = pi*11^2 - pi*4^2
V = integral b/w 1 and 11 of A(x) = ...
Incorrect here as well. Not sure how else to approach this one.
Thanks for help on any of these. At least I got the other 7 problems done on my own. :P
2. Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis:
y = x^2, y = 1; about y = 2.
The resulting solid for me looks like a volcano. So I used the Shell method like so:
A(x) = length * width
A(x) = 2*pi*(x)*x^2 = 2*pi*x^3
V = integral b/w 0 and 1 of A(x) ...
Not getting the right answer here either...
3. A ball of radius 11 has a round hole of radius 4 drilled through its center. Find the volume of the resulting solid.
I tried using vertical washers like so:
A(x) = pi*11^2 - pi*4^2
V = integral b/w 1 and 11 of A(x) = ...
Incorrect here as well. Not sure how else to approach this one.
Thanks for help on any of these. At least I got the other 7 problems done on my own. :P
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