Posted by rachel on .
the area under the curve y= square root of 9x^2 with coordinates x=3 and 3 , find the volume rotated aroudn the xaxis

calculus 
Reiny,
Hey, that's just the top half of the circle
x^2 + y^2 = 9 rotated, giving us the whole sphere
radius is 3,so the volume is (4/3)π(3^3) = 36π
But I guess you want it done using integration....
volume π∫(9x^2) dx from 3 to 3
= π[9x  (1/3)x^3] from 3 to 3
= π(27  9  (27 + 9))
= 36π