Give the equation of the tangent plane and the parametric eq

Give the equation of the tangent plane and the parametric equation of the normal line to the surface z=yCos(x-y) at the point (2,2)

1st compute the vector < dz / dx , dz / dy , -1 > , evaluate at the point , call it < a , b , c > plane : a[x-2] + b [y-2] + c [z - 2] = 0 line : x = 2 + at , y = 2 + bt , z = z(2,2) + ct...you do the easy computations