Finding centroids when integrating with respect to y

[pakmingki]

Homework Statement

no specific problems

Homework Equations

x center of mass = moment about y/total area
y center of mass = moment about x/total area

The Attempt at a Solution

ok, so I am in AP calculus, and since the AP testing has ended, we've done some random topics, such as centroids of constant density regions. So far, we've only found centroids by integrating with respect to x.
So, the formula for the x center of mass coordinate is the [integral from a to b of x(f(x) - g(x))]/total area, and the y center of mass coordinate is [integral from a to b of 1/2 * (f(x)^2 - g(x)^2)]/total area.

Ok, but those formulas only apply to when you integrate with respect to x. What would the formulas be when you integrate with respect to y?

thanks.

 

[Mindscrape]

I am not quite sure if I understand what you are asking. Could you give an example?