What is the inverse triangle symbol represent?

[Outrageous]

Homework Statement

B=magnetic flux density . A is the vector potential of magnetic field. How to get the formula B=∇A

Homework Equations

http://en.wikipedia.org/wiki/Magnetic_moment

The Attempt at a Solution

B=magnetic flux density . A is the vector potential of magnetic field. B=A/(area that is normal to the magnetic field). But how to get the area??
Guide will do. Thank you

 

[SteamKing]

This is the differential operator called del:

http://en.wikipedia.org/wiki/Del

If you are studying magnetic fields, you will also have to study some vector calculus.

 

[Outrageous]

Thank you.^^