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Having an issue with a volume problem, was hoping I could get some help, please. I've got everything figured out on this one, except the limits of integration:
y=2, y=9-X^2 Rotated about y=-1
Normally, I would figure out the points on intersection by setting
9-X^2=2.
Solving this gives me X= +/- Square Root of 7. But when I set my limits to [-sqrt_7,+sqrt_7] they were marked as wrong.
What gives?
Hi jhcasey815,Quote:
Originally Posted by jhcasey815
You could rotate the part of the curve above y=2 around the line y=-1,
or the part of the curve between y=-1 and y=2.
Are you sure which one it is?
If you are rotating the top part above y=2,
you can rotate from x=0 to x=$\displaystyle \sqrt{7}$
and double, or rotate from x=$\displaystyle -\sqrt{7}$ to $\displaystyle \sqrt{7}$
Since the disc radii are $\displaystyle 9-x^2-(-1)=10-x^2$
it's also possible to rotate $\displaystyle 10-x^2$ above y=3 about the x-axis, if you are rotating the top section.
Do you have the full question?
