Consider F(x,y,z)= √(x + yz), P(3,1,1,) and u= (2/7, 6/7, 3/7)
a) Find the gradient of F.
b) Evaluate the gradient at point P.
c) Find the rate of change of f at P in the direction of the vector u.
d) Find an equation of the tangent plane to √(x + yz) = 2j at the point P(3,1,1).