# Finding centroids when integrating with respect to y

1. Jun 3, 2007

### pakmingki

1. The problem statement, all variables and given/known data
no specific problems

2. Relevant equations
x center of mass = moment about y/total area
y center of mass = moment about x/total area

3. The attempt at a solution
ok, so im 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.

Last edited: Jun 3, 2007
2. Jun 4, 2007

### Mindscrape

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