- #1
cpfoxhunt
- 16
- 0
Homework Statement
Prove that for a 3d space s, defined by a function f(x,y,z) = 0 , a unit vector normal to surface at the point (a,b,c) is given by [tex]\nabla[/tex]f(a,b,c) / modulus of [tex]\nabla[/tex]f(a,b,c)
(Apologies for the bad use of latex)
Homework Equations
None really
The Attempt at a Solution
I can only seem to gesture at this - it was given us as a definition. I know that d(phi)/ds where phi is a surface and s is a distance = [tex]\nabla[/tex](Phi).A , and that surely if a is tangential the LHS is equal to zero, but I'm a bit stuck from there and not sure if I've used things I need to prove. Its only a few marks, but is bugging me.
Any help is greatly appreciated,
Cheers
Cpfoxunt