the normal vector to the tangent plane at (x,y,z) is where thus: the vector from the origin to the point (x,y,z) is (x,y,z).

so we want to find all points on the surface that satisfy the equation for some that gives us: thus we just need to solve the following

system of equations: i hope you can take it from here! you should consider the cases and separately. similarly for you will get 5

points that satisfy the above system of equations.