Calculus
posted by Christina on .
Find the volume or the solid generated by revolving around the region bounded by the graphs of the equations about line x=6. xy=6, y=2, y=6, and x=6

y=2 intersects xy=6 at (3,2)
So we are rotating the region bounded by
(3,2) to (6,2), then down to (6,1) and joining the curve back to (3,2)
Vol = π∫(6x)^2 dy from y = 1 to 2
= π∫(36  12x + x^2) dy
=π∫(36  12(6/y) + 36/y^2) dy from 1 to 2
= π[ 36y  72lny  36/y ] from 1 to 2
= π( (72  72ln2  18)  (36  72ln1  36) )
= π(54  72ln2)
= 18π(3  4ln2) or appr 12.86
check my arithmetic