Is A Cross B Equal to Zero a Test for Orthogonal Cases?

[Philosophaie]

A cross B equals zero is a test for orthogonal cases.

If AxB=0 then A is perpendicular to B.

 

[Number Nine]

Uh...is that a question?

 

[HallsofIvy]

A cross B equals zero is a test for orthogonal cases.

If AxB=0 then A is perpendicular to B.

No, it's not. It is the dot product. If A and B are vectors, the $A\cdot B= 0$ if and only if they are orthogonal (perpendicular).

You are confusing this with the fact that if A and B are any two (three dimensional) vectors, then $A\times B$ is perpendicular to both A and B.