What is the maximum rate of change of the function: f(x, y) = 3x + 3y at (3, 1)? In which direction is this maximum achieved (enter a unit vector)? (Unless otherwise specified, always enter exact values, not a decimal approximation) The maximum rate of change is A unit vector in the direction of this rate of change is ( Check (3) Overview standard function logic vector abc unit Search W ENG 5:31 PM US 27/8/2023 F3 F4 F5 FO F8 FO F1 La Insert Delete 8 Bockspace O D