Question

True or False

a) a*(axb)=b*(axb)=0

Answer 1

I say true

Answer 2

....

Answer 3

Is that a dot product and cross product?

Answer 4

If they are, then recall that a cross product produces a vector perpendicular to BOTH vectors. Also recall what happens when you dot a vector with another that is perpendicular to it. It's zero. That's what's happening here.