9.5k views
1 vote
if vectors A&B are non zero vectors ,is it possible for their dot product and cross product to be zero? explain.​

User MoneyBall
by
5.2k points

1 Answer

2 votes

Answer:

It can be proved that it’s impossible.

The dot product is defined as:

a⋅b=∥a∥∥b∥cos(θ)

where θ is the angle between a and b .

The cross product is defined as:

a×b=∥a∥∥b∥sin(θ)n^

and the magnitude of this is given by:

∥a×b∥=∥a∥∥b∥sin(θ)

We also know that:

cos2(θ)+sin2(θ)=1

We can substitute the dot product and the magnitude of the cross product in here, to find:

(a⋅b)2+∥a×b∥2=∥a∥2∥b∥2

We’ve specified that a and b are non-zero vectors, so the right hand side cannot be zero. As a result, at least one of (a⋅b)2 or ∥a×b∥2 must be non-zero.

Explanation:

User Evamvid
by
5.2k points