For $1-6,$ set up and evaluate the integral that gives the volume of the solid formed when the region bound by the given lines is revolved about the $x-$axis. For $1$ and $2,$ use a GDC$.$

$*1.y=3-\frac{x}{3},y=0,x=2,x=3$

$*2.y=2-x^2,y=0$

$3.y=\sqrt[\phantom{2}]{16-x^2},y=0,x=1,x=3$

$4.y=\frac{3}{x},y=0,x=1,x=3$

$5.y=secx,x=\frac{}{4},x=\frac{}{3},=0$

$6.$ The volume of the solid formed by revolving the region bound between the given lines about the x $-$axis is $a*2^b.$ Find a and $b.$

$y=\sqrt[\phantom{2}]{2x},y=x^2$