The question is:

Find the Cartesian form of the equation for the plane that is perpendicular to the space curve

at the point P(32, -32, 16).

-----------

Now the simple part of course, once I have the normal (n) to the curve at P, I can construct a plane equation via

where

(the vector from the plane's origin (P) to any point Q).

Of course, I can find the derivative of r(t), which is:

That will give me the tangent vector at any time

**t**.

I know that t = 16, from the 'k' component, so I can evaluate

But I need the normal vector (perpendicular to the curve).

Any tips?