Question

Find the exact coordinates of the centroid. y = sqrt[x], y = 0, x = 9.
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Is this basically 1/4 of an oval/ellipse? If so then the area would be: pi*9*3, correct?

So the X coordinate would equal: 1/Area * Integral from 0 to 9 of (x*f(x))*dx
Which equals: (4/(27*pi))*[(2/5)(x^(5/2))] evaluated at 9 and 0 which equals: 4.584?

The Y coordinate would equal: 1/Area * Integral from 0 to 3 of (1/2)*[f(x)]^2*dx
Which equals: (4/(27*pi))*(x^2)/4 evaluated at 3 and 0 which equals: 0.955

Am I using the wrong equation for area?