integration/volume of rotation question (1 Viewer)

[modular]

would someone be kind enough to see if ive answered this question correctly

ive done all the working, its shown in the file below. the part im unsure of though is 1.c

if someone could take a quick look id be very very grateful !


question + answer in files below

 

[Ali92l]

Your answer is right, Pie u^3 ./