Suppose That as You Move Away from the Point (-1 $f ( x , y , z )$

Suppose that as you move away from the point (-1, -1, -1), the function $f ( x , y , z )$ increases most rapidly in the direction $0.6 \vec { i } + 0.8 \vec { j }$ and the rate of increase of f in this direction is 4.At what rate is f increasing as you move away from (-1, -1, -1)in the direction of $\vec { i } + \vec { j } + \vec { k }$ ? Give your answer to 4 decimal places.