Find the unit vectors perpendicular to both and
when
and
Let be the vector which is perpendicular to
then we have,
…where k is a scalor
Thus, we have r is a unit vector,
So,
We have,
Here,
We
have
⇒
Thus, substituting the values of ,
in equation (i) we get
⇒
⇒
⇒
⇒