QUESTION 2 (20 MARKS) (a) Evaluate the integral (2x + y?) dx dy. by first converting it into an integral in polar coordinates. (7 marks) (b) Find the mass of the solid in the first octant bounded by the planes y = 0, z = 0 and y = x, and z = 4 - x2 with density 6(x, y, z) = Ty. (6 marks) (c) Evaluate the integral . 1-x2-ya 22 dz dr dy. (15.1) I? + y2 + 22 by first converting it to an integral in spherical coordinates. (7 marks)