# Math Help - Normal to a Surface

1. ## Normal to a Surface

I'd be VERY grateful for any help anyone can offer!

Find the normal vector to the surface described by:

I really have no idea where to begin. I can find the partial derivatives but not sure if I even need to use them.

Thanks for any help!

2. Originally Posted by Spimon
I'd be VERY grateful for any help anyone can offer!

Find the normal vector to the surface described by:

I really have no idea where to begin. I can find the partial derivatives but not sure if I even need to use them.

Thanks for any help!
Ummmm, this is an ellipsoid. There are going to be many many normal vectors to this. (Any vector is normal to it at some point on the surface, in fact.) Do you have a specific point you need to find a normal at?

-Dan

3. Thanks for the reply.

The first question is to just find the normal vector to the surface. I suppose that means the general formula for the normal in relation to x,y,z?

The next part is to find the normal at the point

Sorry, I'm very lost with this concept. I understand the normal to a plane is the cross-product of the 2 vectors by which it is bound, but I have no idea how to find the normal to a surface. I did find some material on the net but it's in such ambiguous mathematical terms I can't understand it cearly.

- Simon