MathMate - look at this
posted by Reiny .
perhaps you can shed some light on this
I seem to have a "mental block" here.
Yeah, it was a nice little puzzle.
I would have left it as 9x/(2π) which is normal practice for maths answers. I responded in detail at the original post.
ok, arclength of course!
For some reason I had the wheel rotating and was looking for the up-down motion similar to a ferris-wheel.