1. The problem statement, all variables and given/known data I need to find the unit normal vector to x2+z2=16. I can find the unit normal vector to every shape but a cylinder, and I can't seem to see how to do it. 2. Relevant equations [tex]\nabla[/tex]F=Fxi+Fyj+Fzk 3. The attempt at a solution I know that I need to find the gradient of the surface equation. I've considered that this gradient may be i-2x-2z. Or am I completely wrong? If you need more information please say what. Thank you!