Find the volume of the solid of revolution that is formed by
rotating the region bounded by the graphs of the equations given
around the indicated line or axis
1.- y=9-x^2, y=0, around the x axis
2.- y=√x-1, x=5, y=0, around the x=5
3.- y=1-x, x=0, y=0, around the y= -2
4.- y=x^2, x=0, y=3, around the y axis