- #1
Stuart Caffre
- 5
- 0
Homework Statement
Prove using the Levi-Civita Tensor/Kroenecker Delta that:
(AxB)x(CxD) = (A.BxD).C-(A.BxC).D
Homework Equations
εіјkεimn = δjmδkn – δjnδkm (where δij = +1 when i = j and 0 when i ≠ j)
The Attempt at a Solution
if E = (AxB) then Ei = εіјkAjBk, and
if F = (CxD) then Fm = εimnCnDi
from this point I'm a little confused as I'm not sure if I have to find the cross product of (ExF) using the summation notation, or if I can now relate these via the Kroenecker delta relationship given. I feel I am missing a step as there are 3 cross product relationships and I would greatly appreciate some help here as the only examples I can track down deal with 2 cross product relationships.
Thanks very much in advance
PS
Apologies for the the lack of proper subscripts but that's a problem for another day