# Dot product between cross products

## Homework Statement

show (axb) . (cxd) =
|a.c b.c|
|a.d b.d|

## The Attempt at a Solution

i have no idea. i don't know if the lines at the side are modulus lines or matrix brackets

but it seems that it has something to do with distribution law.

but i can't start proving if i don't even understand what the right hand side of the equation is ><

thanks for help!