What is the surface area of the solid created by revolving f(x)=x3 for x[1,2] around the x-axis?

1 Answer
Mar 17, 2016

24.93

Explanation:

Surface area of solid of revolution about x axis is given by the formula

S=ba2πyds=ba2πy1+(dydx)2dx. In the present case ,
dydx=32x12, hence 1+(dydx)2=1+9x4

S=2π21x321+9x4dx

=π21x329x+4dx

This integration is too long to write it here. hence
use integral calculator to solve the integral

= 24.93