# Volumes of Revolution Help (1 Viewer)

#### alussovsky

##### Member
I got this question as part of my homework:
"Find the volume generated when the curve $\bg_white y=e^{x}$ between $\bg_white x=0.5$ and $\bg_white x=1.5$ is rotated about the $\bg_white x$-axis."

(So correct me if I'm wrong, but the equation is $\bg_white V= \pi \int_{0}^{1.5} e^{2x} dx - \pi \int_{0}^{0.5} e^{2x} dx$, right?)

Going by the above equation, I got the answer $\bg_white \frac{1}{2} \pi (e^3-e)$. However, the answer is $\bg_white \pi(e^3-e)$.

What have I done wrong?

Last edited:

#### HeroWise

##### Active Member
You are right seeing the 1/2 comes from integaration of e^2x, Btw you shouldnt calculate total volume minus unnecassry always. You will be wasting time. You can go from 0.5 to 1.5