A2.1 Find and classify the stationary points of the function given by 1 f(a:,y) : 3:53 + y3 + 21:2 123: 3y. [5] A22 For each of the following, sketch the region of integration and evaluate the double integral by calculating a repeated integral with appropriate limits: (3') [/xgydxdya R={(x,y):0sxs3,lsysz}; R (a) ff sine: y) my, 8 = {(33311) = o s a: s mo 3 y s w/s}; S where R and S are rectangles. [5]