- #1
PirateFan308
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Homework Statement
Find the volumes of the solids revolution obtained by rotating the region about the x-axis and the y-axis.
[itex]y=2x-x^2, y=0[/itex]
The Attempt at a Solution
I know how to get the volume of a function that is rotating around one axis, but the "y=0" is confusing me. Because [itex]y=2x-x^2[/itex] is a parabola (with a max at (1,1)), so when I picture it, it looks like a squished donut (with the hole having no area), where a cross sectional area of the donut is shaped like a football with the area being 4/3 (integral of [itex]f(x)=2x-x^2[/itex] from 0 to 2). The outer radius will be 2 and the inner radius will be 0.
Is this correct, or am I completely off track? Also, what does the y=0 mean? Thanks