Find the extremum of f(x,y) subject to the given constraint, and state whether it is a maximum or a minimum. f(x,y) = x2 + 4y2; 2x + 2y=40 . . . There is a value of located at (x, y) = (Simplify your answers.)Find the relative maximum and minimum values. f(x,y) = x + yz+ 18x-20y . . . Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. O A. The function has a relative maximum value of f(x,y) = at (x,y) = (Simplify your answers. Type exact answers. Type an ordered pair in the second answer box.) O B. The function has no relative maximum value.dP Answer parts (a) and (b) using the inhibited growth model - = k(L - P). Let L = 4000, and assume that P passes dt through the point (16,440). Assume that P(0) = 0. a) Find the particular solution P. b) When will P(t) = 0.8L? . . . a) P(t) = (Type an exact answer in terms of e. Use integers or decimals for any numbers in the expression. Round to five decimal places as needed.)