Cost Function. Suppose the cost to manufacture a product is given by My) = In(xy2) The domain of f(x,y) is the set of all points (my) in the xy-plane where x 2 o and y 2 0 O the set of all points (my) in the xy-plane where x z 0 O the set of all points (my) in the xy-plane where y a o 0 none of the other answers Q the set of all points (my) in the xy-plane Composition. Suppose we want to find the composition of a function with itself. Let g(x) = 4(X+3)2 Then the function(g o g)(x) equals 0 16(x+3)4 O 4(x+3)2 O 4(x+3)2 4(4x2 + 24x +39)2 0 15(x+3)4 O 4(4x2 + 24x +39) 0 4(4x2 + 24x+39)2 O 4(4x2 + 24x+39) .. B cycles. A local company that manufactures and sells bikes has found that its monthly revenue (in dollars) is given by R(x,y) = 5 x2 2.5 y2 Sxy + 500x+ 320 y where X is the number of mountain bikes and y is the number of city bikes that it sells each month. (a) The critical point of R(x,y) is 0 (60,50) 0 (0,0) 0 (15,80) 0 (80,15) 0 There is no critical point 0 (50,60) (9 (36,28) 0 (28,36) (b) Let D(x,y)=RXX(x,y)Ryy(x,y)ny2(x,y). Suppose that a is the number of mountain bikes and b is the number of city bikes that should be sold each month to ensure a maximum monthly revenue. Which of the followir D(a,b) > o and RXX(a,b) o and Rxx(a,b) > o O D(a,b) = o O D(a,b) 0 O D(a,b)