Find surface area of solid formed by rotating the following curve about the y-axis:

on

*The "a" in there kinda screwed me up, but this is my work:

When I solved for the arc length, I ended up getting , like this:

**Is this right?

So my integral is:

Then I pulled my square root out in front:

I have more, but can some one check this up until this point?

Thanks!! Molly