# Surface Area

Printable View

• Dec 10th 2007, 02:49 PM
MathNeedy18
Surface Area
I think I am getting the wrong equation! and I keep going over it and over it and keep getting the same. HELP PLEASE!

Find the area of the surface generated by revolving the following curve about the http://webwork1.math.utah.edu/math12...850965img1.gifaxis:

Area of the surface: .
• Dec 10th 2007, 04:04 PM
galactus
Are you using the correct formula. In parametrics, revolving about the x-axis, surface area is given by:

$2{\pi}\int_{0}^{\pi}rsin(t)\cdot\sqrt{r^{2}sin^{2} (t)+r^{2}cos^{2}(t)}dt$

Which reduces to:

$2{\pi}r^{2}\int_{0}^{\pi}[sin(t)]dt$

Which gives the surface area of a sphere.
• Dec 10th 2007, 04:10 PM
MathNeedy18
Thanks a bunch! I forgot to write down the rsin(t)!!! BAH!(Tmi)