4. Let f(x, y, z) = x'es, and suppose r(s, t) = to, y(s, t) = s' + cost, z(s, t) = . Compute of at as a function of s and t. You do not need to simplify your answer. 5. Let f(x, y) be a function with a = In(s + 2t) and y = (s + 1) . cost. Below is a table of certain values of fr and fy- (x, y) | fx(x, y) | fy(x, y) (1, 0) 3 5 (0, 2) -2 Find the value of " when (s, t) = (1, 0). (Hint: Some values in the table will not be useful.)