Finding A and B to Satisfy A X B = B

[student 1]

Homework Statement

Can A X B = B? If so, find A, and illustrate with a picture
B. If A=A_xi+A_yj, find B such that A X B = A_yi-A_xj

Homework Equations

I know A X B= ABsin$$\theta$$

The Attempt at a Solution

 

[Nick89]

You have missed the important part:

The Attempt at a Solution

Show some work, we won't simply give you the answers here!

I will give you one hint though. The expression you gave (AxB = ABsin..) is technically not correct.
The correct expression is:
$$\left| \vec{A} \times \vec{B} \right| = \left| \vec{A} \right| \left| \vec{B} \right| \sin \theta$$

In other words, it only gives you the length of the vector. Don't forget what a vector is!

 

[student 1]

Well i just need to know how to begin. I know If A is only in the x,y plane and B is only in the x,y plane then there's no way that's possible. However i don't know how to determine it with 3 different axis.

 

[D H]

Don't forget what a vector is!

Student1, a vector is something with a magnitude and a direction.

 

[Nick89]

If you have:
$$\vec{A} \times \vec{B} = \vec{C}$$,
what do you know about the vector C in relation to A and B?