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Find the volume created by revolving:
y=x^2 +x - 2
and y=0 about the x axis.
y=x^2 +x - 2 intersects the x-axis at -1 and 1 so those are the bounds of integration.
the radius of the figure = -(y=x^2 +x - 2)
so:
V = - \pi \int_{-1}^1 (x^2 + x - 2)^2 dx
After integrating that I get 18\pi/5. The actual answer is 81\pi/10. What I want to know is if i set the integral up right. If I did then this is only a stupid integration mistake. If not then I hope someone finds my mistake. Thanks for the help.
y=x^2 +x - 2
and y=0 about the x axis.
y=x^2 +x - 2 intersects the x-axis at -1 and 1 so those are the bounds of integration.
the radius of the figure = -(y=x^2 +x - 2)
so:
V = - \pi \int_{-1}^1 (x^2 + x - 2)^2 dx
After integrating that I get 18\pi/5. The actual answer is 81\pi/10. What I want to know is if i set the integral up right. If I did then this is only a stupid integration mistake. If not then I hope someone finds my mistake. Thanks for the help.
