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).

Afootball is passed through the air and caught at ground level for a touchdown. the height of the ball (h) is given by h= -d² + 12d + 6, where d is the distance in feet the ball travels horizontally. how far from the player passing the ball will the ball be caught? 40 points! will mark brainliest!