Integratin problem

Question

Set up, but do not evaluate, the integral which gives the volume when the region bounded by the curves y = Ln(x), y = 1, and x = 1 is revolved around the line y = −1

Answer 1

Definite integral (from x=1 to x=e) of Integrand  pi(R²-r²)  dx

where R = 2 and r = 1+lnx   ⇐"WASHERS cross section method"

 

Make the sketch and reason it out!