In Exercises 7-14, use the Shell Method to compute the volume obtained by rotating the region
enclosed by the graphs as indicated, about the y-axis.
7. $y = 3x - 2$, $y = 6 - x$, $x = 0$
8. $y = \sqrt{x}$, $y = x^2$
9. $y = x^2$, $y = 8 - x^2$, $x = 0$, for $x \ge 0$
10. $y = 8 - x^3$, $y = 8 - 4x$, for $x \ge 0$
11. $y = (x^2 + 1)^{-2}$, $y = 2 - (x^2 + 1)^{-2}$, $x = 2$
12. $y = 1 - |x - 1|$, $y = 0$
13. $y = 2 - x^4$, $y = x^2$, $x = 0$, for $x \ge 0$
14. $y = \sqrt{x^2 + 9}$, $y = 0$, $x = 0$, $x = 4$
