These are the formulas for the centroids of the area under the curve f(x) or f(y):

(a, b are the bounds of the curve for x and c, d are the bounds for y)

Then,

The origin is at

As our function is a function of x, we'll use the formulas on the left side of the table.

Firstly, this is the graph:

Find

Hence,

So the centroid is at