thanks! My only question here is how did you get from 18/x to the radical formula? thanks again
You substitute $\displaystyle y' = \frac{dy}{dx}$ into the given formula $\displaystyle
\int_{a}^{b} \sqrt{1+(y')^2} \, dx$. You are familiar with this arclength formula, right?
mr fantastic- ah I see now, I was actually not familiar with that formula, its a calc 2 online course, and the notes provided by the prof. are pretty difficult to decipher, now I've found the section though, thanks!