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oooride
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I'm having trouble coming up with the correct solution to a number of these questions.. This is one I've been stumped on..
Find the Volume of the solid that results when the region enclosed by the given curves is revolved about the x-axis.
y = sqrt(25-x^2), y = 3
Since I believe it is a washer method, what I did was:
V = int pi[f(x)]^2 - [g(x)]^2 dx
= pi int{-5to5} [25-x^2] - [9] dx
= pi int{-5to5} [25x-x^3/3] - [9x]
= pi [(-125) + (125/3) + (45)] - [(125) - (125/3) - (45)]
= pi (365/3) - (115/3)
= 250pi/3
The book says 256pi/3, which part am I doing wrong?
Any help is greatly appreciated.
Thanks.
Find the Volume of the solid that results when the region enclosed by the given curves is revolved about the x-axis.
y = sqrt(25-x^2), y = 3
Since I believe it is a washer method, what I did was:
V = int pi[f(x)]^2 - [g(x)]^2 dx
= pi int{-5to5} [25-x^2] - [9] dx
= pi int{-5to5} [25x-x^3/3] - [9x]
= pi [(-125) + (125/3) + (45)] - [(125) - (125/3) - (45)]
= pi (365/3) - (115/3)
= 250pi/3
The book says 256pi/3, which part am I doing wrong?
Any help is greatly appreciated.
Thanks.