Help settle a dispute with a friend. I got 16/3(3*sqrt(3)-1)pi whereas she got 8*pi*sqrt(2x+1).
Find the area of the surface obtained by rotating the curve about the x-axis. y=sqrt(1+2x), 1

Question

Help settle a dispute with a friend. I got 16/3(3*sqrt(3)-1)pi whereas she got 8*pi*sqrt(2x+1). Find the area of the surface obtained by rotating the curve about the x-axis. y=sqrt(1+2x), 1

phi · Answer

8*pi*sqrt(2x+1) is not a fixed number (because it has an x)
that does not make you right, but it does make your friend wrong.

clarence · Answer

Oh yeah! Whoops, my bad, and thanks for correcting me!

clarence · Answer

Are you definitely sure about the positive sign though?

phi · Answer

oops, you are correct as posted.

clarence · Answer

Aha, all good, just thought I'd double check it, thanks again!