[Donnah (OP)]

Hey everyone!
Donnah's son again []
New question, although a bit more mathmatical in nature.
In my calculus class, we have been debating a bit about how to find the surface area of an ellipse.
I have a pretty good theory as to how to get the perimeter, but still the SA eludes me.  Anyone Know?
Thanks
-Steve

[Dan B]

Integrate your circumference from 0 to 2pi.

[Ylide]

Or, if line integral aren't your thing, you can do it with a basic cartesian equation of the ellipse.

Center the ellipse on the origin and write it as an equation, X^2/a^2 + Y^2/b^2 = 1.  (where a is the X-axis radius and b is the y-axis radius)  Solve for Y = f(x)  and you have the equation for one half of the ellipse.  Integrate the equation f(x) over the length in the x-axis and you have the area under the top half of the ellipse.  Now double it, and there's your answer.



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[chris]

Wow, nicely done !

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[Ylide]

A year and a half of calculus had to be good for something.



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