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Volume of an object rotated on xaxis
Posted:
May 27, 2013 9:34 AM


Hi guys and girls,, this is my first post here so hi to everybody ! :)
Ok my questions is how do i calculate the volume of an object rotated on the xaxis
I have to functions f(x) = 2*sqrt(x) & g(x) = 8x
fist i calculate the area from 0 to 4(Their intersection)
aw = g(x)  f(x) int(aw, 'x', 0, 4)
it spits out : 40/3 which is correct
Now i have to rotate it against? the xaxis and calculate the volume
V = pi * int(aw^2, 'x', 0, 4) V = (928*pi)/15
Which is not the same answer as i have on my page with answers The result on the page is : (352*pi)/3
What am i doing wrong? :(
Sorry for my english Thankes !



