Let (S) be the paraboloid z=10-(x-1)^2-(y-2)^2 and let M be the highest point (relative to the plane Oxy) on (S ). Let (P) be the tangent plane to (S) at M. Which point from the following is on the plane (P) ? 

Show work please

At what point on the paraboloid y=x²+z² isthe tangent plane parallel to plane x+2y+3z=1 ?

Where does the helix   intersect the paraboloid ? What is the angle of intersection between the helix and the paraboloid? (This is the angle between the tangent vector to the curve and the tangent plane to the paraboloid.)