its urgent. kindly do it fast i will give more reviews

Q4 (a) Evaluate the limit lim xy cos y if it exist. If not, show that the limit does not (x,y)-(0,0) 3x2+y exist. (5 marks) (b) Given z = x2(1 + y)3, the value of (x,y) changes from (2,9) to (2.03,8.9). Use the total differential to find the approximate value and also exact value for z. (7 marks) (c) A lamina enclosed between the circle x2 + y2 = 1 and x2 + y? = 4, and x=0 (upper half of annulus) has density function o (x, y) = yx2. Find its mass. (8 marks)