4. [011 Points] DETAILS PREVIOUS ANSWERS LARCALCEW 13.6.004. MY NOTES ASK YOUR TEACH Use Theorem 13.9 to find the directional derivative of the functien at P in the direction of the unit vector u = cos 9i + sin 3i. may): y , 130,0), ezl 3X+y 6 Need Help? _ Viewing Saved Work Revert to Last Response 5. [011 Points] DETAILS PREVIOUS ANSWERS LARCALCEW 13.6.005. MY NOTES ASK YOUR TEACH Use Theorem 13.9 to nd the directional derivative of the function at P in the direction of the unit vector u : cos Hi + sin Hj. for. y) = sin(6x + y}. Pro, at), e = 5?\" Ex Need Help? Submit