3. The centroid of a region R in the my-plane having area A is the point with Cartesian coordinates (E, 3]) given by i=i/medmdy, y=ifydmdy. (The centroid would be the centre of mass if a plate in the shape of R was made out of a uniform density material.) Find the centroid (LE, 37) of the circular sector given by the polar coordinate inequal ities, 0$TSR03 OSQSQO: where 0