# Outer differentiation?

by Creator
Tags: differentiation, outer
 P: 559 Since I didn't get a response on the "Diff. Eqns." thread, I put it here. Can someone give me a clear explaination of what is meant by "outer" differentiation. As for example, when we differentiate the vector potential, dA/dx, in order to arrive at the magnetic field, B, why would this be called an 'outer' differentiation?? [?]
HW Helper
P: 2,327
 Originally posted by Creator ... when we differentiate the vector potential, dA/dx, in order to arrive at the magnetic field, B, why would this be called an 'outer' differentiation??
Probably because d/dx is not exactly what you do. You take the cross product of the gradient operator with the vector potential to get the magnetic field. The cross product is sometimes called/related to the outer product, but that's tensor jargon with which I am unfamiliar.
 P: 559 Thanks for the response, Turin; and thanks for the correction. Oc course, you are accurate in saying it is the cross product of the gradient. I guess then if someone says "dA/dt is the outer differentiation" I should interpret that to mean they are simply referring to it as being a cross product.??
HW Helper
P: 2,327
Outer differentiation?

 Originally posted by Creator ... if someone says "dA/dt is the outer differentiation" I should interpret that to mean they are simply referring to it as being a cross product.??
I would ask them what they mean. I wouldn't know how to make sense of that.

 Related Discussions Calculus & Beyond Homework 9 General Discussion 9 Differential Equations 0 Calculus 3