3. Let r = r(x, y), x = x(s, t) and y = y(t). Find of at (s, t) = (1, 0) given x(1, 0) = 2, Is(1,0) = -1, It(1,0) = 7, y(0) = 3, y(1) = 0, y' (0) = 4, r(2, 3) = -1, Tx(2, 3) = 3, Ty (2, 3) = 5, Tx(1, 0) =6, rt(1, 0) = -2. 4. If h = x2 + y' + 2 and ycos z + z cose = 0, find Oh assuming that x and y are the independent variables.5. Decide whether each statement is true or false. If true, explain what strategy you would use to find the absolute maximum and minimum values. (a) Every continuous function f(r, y) must attain an absolute minimum and absolute maximum value on * + 4y'