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anonymous
 5 years ago
Find the volume of the solid generated from revolving y = sqrt(4x^2) around the x axis.
anonymous
 5 years ago
Find the volume of the solid generated from revolving y = sqrt(4x^2) around the x axis.

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saifoo.khan
 5 years ago
Best ResponseYou've already chosen the best response.0amistre, please help me asap.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1i think this would be infinite without bounds

saifoo.khan
 5 years ago
Best ResponseYou've already chosen the best response.0Ben he will be back dont worry. i have 3mins. ;(

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0well it has zeros at 2 and 2 i think. i ended up getting an answer i just dont know how to check it. i got 32pi/3

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1to check, wolframalpha does a wonderful job

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.12pi is what the wolf gives us http://www.wolframalpha.com/input/?i=integrate+sqrt%284x%5E2%29+from+2+to+2

saifoo.khan
 5 years ago
Best ResponseYou've already chosen the best response.0Amistre, another question please?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1if we do what is commonly refered to as a disc method we add up the areas of a bunch of circles; A = pi r^2, where r = our given function.\[pi\int _{0}^{2}(\sqrt{4x^2})^2dx\] \[pi\int _{0}^{2}(4x^2)dx=pi(4x\frac{1}{3}x^3)\] \[pi(4(2)\frac{1}{3}2^3)0\] \[pi(8\frac{8}{3})\]i see the conundrum alright :/

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what is wrong with that?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0and souldent it be 2pi on the outside of the integral? you would either have to do it from 2 to 2 or you would need to do 2pi integral from 0 to 2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1nah, the area of each circle is: pi [f(x)]^2 and we add all those up from 2 to 2, or just from 0 to 2 and double it

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1(sqrt(a))^2 = a so we can forgo the sqrt in the integration int 4  x^2 4 ups to 4x x^2 ups to x^3/3 4x  x^3/3 at 0 = 0 at 2 = 8 8/3 = 16/3 and not to forget the pi http://www.wolframalpha.com/input/?i=integrate+pi%28sqrt%284x%5E2%29%29%5E2+from+0+to+2 now the wolf agrees

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1so yeah, 32/3 pi should be it

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.1i see, i entered it wrong at the start of all this .... it sucks getting old lol

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0haha ok cool thank you
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