
Las Fórmulas del centro de masas son:
$$\begin{align}&x_c=\frac{\int \int_R x \gamma (x,y,z) dydx}{\int \int_R \gamma (x,y,z)dydx}\\&\\&y_c=\frac{\int \int_R y \gamma (x,y,z) dydx}{\int \int_R \gamma (x,y,z)dydx}\\&\\&donde \gamma (x,y,z) \ es \ la \ función \ densidad.\\&En \ este \ es \ constante \ y \ la \ suponemos \ 1\\&\\&x_c=\frac{\int \int_R x dydx}{\int \int_R dydx}\\&\\&y_c=\frac{\int \int_R y dydx}{\int \int_R dydx}\\&\\&\int \int_R xdydx= \int_0^6 \int_0^{x^2-4x-6} xdydx=\int_0^6xy \Bigg|_0^{x^2-4x+6} dx=\\&\\&\int_0^{6}x(x^2-4x+6)dx= \int_0^6(x^3-4x^2+6x)dx=\\&\\&\Bigg[\frac{x^4}{4}-\frac{4x^3}{3}+\frac{6x^2}{2} \Bigg]_0^6=324-288+108=144\\&\\&\int \int_R ydydx=\int_0^6 \int_0^{x^2-4x-6} ydydx=\int_0^6 \frac{y^2}{2} \Bigg|_0^{x^2-4x+6}dx=\\&\\&\frac{1}{2} \int_0^6(x^2-4x+6)^2dx=\frac{1}{2} \int_0^6(x^4+16x^2+36-8x^3+12x^2-48x)dx=\\&\\&\frac{1}{2} \int_0^6(x^4-8x^3+28x^2-48x+36)dx=\\&\\&\frac{1}{2} \Bigg[\frac{x^5}{5}-\frac{8x^4}{4}+\frac{28x^3}{3}-\frac{48x^2}{2}+36x \Bigg]_0^6=\\&\\&\frac{1}{2}\Bigg(\frac{7776}{5}-2592+2016-864+216 \Bigg)=165.6\\&\\&\int\int_Rdydx=\int_0^6 \int_0^{x^2-4x-6} dydx= \int_0^6 y\Bigg|_0^{x^2-4x+6}dx=\\&\\&\int_0^6(x^2-4x+6)dx=\Bigg[\frac{x^3}{3}-2x^2+6x \Bigg]_0^6=72-72+36=36\\&\\&x_c=\frac{144}{36}=4\\&\\&y_c=\frac{165.6}{36}=4.6\\&\\&Centroide=(4;4.6)\\&\\&\end{align}$$