Answer
$V=\int_m^n 2 \pi (Shell \ Radius) \times (Shell \ height) \ dx$
Work Step by Step
The volume $V$ of a solid region generated by revolving the region bounded by $y=f(x)$ between the x-axis and the graph of a continuous function $y=f(x)$ on the interval $[m,n]$ about the x-axis, and $L \leq m \leq x \leq n$, about a vertical line $x=L$ from $x=m$ to $x=n$ can be defined as
$V=\int_m^n 2 \pi (Shell \ Radius) \times (Shell \ height) \ dx$
