For each region, select the positive integer $nso$ that the volume $V$ when the region $is$

rotated about the line $xyisin$ the given range. Whether the line you're looking

for $is$ vertical $or$ horizontal $is$ given $in$ each part.

$(a)(3$ points$)y=ln(x^2+1),x=1,y=0,1V3$

$x=$

$(b)(3$ points$)y=(1-x)arctan(\sqrt[\phantom{2}]{x}),y=0,3V5$

$x=$

$(c)(3$ points$)y=cos(\sqrt[3]{x}),y=0,100V110$

$y=$