Theorem
Ifandare sets of reciprocal vectors, and(1) then
Proof
Sinceandare perpendicular sets,
Substitute (1) into these expressions, obtaining
Then
Now use the identityhence
Theorem
Ifandare sets of reciprocal vectors, and(1) then
Proof
Sinceandare perpendicular sets,
Substitute (1) into these expressions, obtaining
Then
Now use the identityhence