Find the directional derivative using f(x, y, z) = xy + z2. At the point (4, 2, 4) in the direction of a vector making an angle of 3π/4 with grad f(4, 2, 4).

The distance between a football fsaid and a parking lot is 135 feet. what is that length in yards? 2 mickey needs to cut pieces of ribbon that are each 1 meter long to tie onto balloons. if he has 8 pieces of ribbon that are each 1 dekameter long, how many 1-meter pieces of ribbon can he cut? show work