# Math Help - tangent.....

1. ## find equation of the tangent and normal plane......

Hello,
plz try to solve that question.Thanks

2. here's a hint for the tangent plane: take the gradient of the equation. If you get something like x^2 * y +z ^ 32 * x*y, then next you need to write the equation of this tangent plane. As this is the (fictional) gradient, you need to consider what would happen near the point P(1,2,3), which implies considering (x-1)^2 * (y-2) + (z-3)^32 * (x-1) * (y-2). Now, I may be wrong, because the problem asks for a tangent plane, but the above equation (and the one you'd obtain taking the gradient in your question) is not actually a plane, i.e. you cannot express your gradient as Ax+By+cZ=D (sound familiar? it's the general equation for a tangent plane), where A,B,C,D are all constants.

The normal plane is left to you. If you want more advice, do more work.