Question 5: (4 points) Format: • If your answer below is a vector, input it as a column vector using the vector/matrix palette tool. • Use * to explicitly indicate multiplication

between variables and other variables, between variables and brackets, or between sets of brackets (e.g. x*y rather than xy; 2*(x+y) rather than 2(x+y)). • Put arguments of functions in brackets (e.g. sin(x) rather than sin x). • Give your answers in exact form. Find the directional derivative of f(x, y, z) = -13 xy² + 11xz² + 5y at P= (-2,-3, 2) in the direction of (1, -2,-5). D(1,-2,-5) | (-2,-3,2) What is the maximum rate of increase of f at P? |vf|(-2,-3,2)=