Aysce
Well-Known Member
- Joined
- Jun 24, 2011
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- HSC
- 2012
Hello.
Q. Rotate y=4-x^2 around the x-axis by taking slices perpendicular to the axis of rotation and find the volume enclosed.
I know the process to do it but looking at the diagram of the solution, I am unsure of how the parabola intersects the y-axis at 4 and -4, and why it intersects the x-axis at x=2.

Thanks in advance!
Q. Rotate y=4-x^2 around the x-axis by taking slices perpendicular to the axis of rotation and find the volume enclosed.
I know the process to do it but looking at the diagram of the solution, I am unsure of how the parabola intersects the y-axis at 4 and -4, and why it intersects the x-axis at x=2.

Thanks in advance!