# Homework Help: Vector Product

1. Jul 16, 2008

### student 1

1. The problem statement, all variables and given/known data
Can A X B = B? If so, find A, and illustrate with a picture
B. If A=Axi+Ayj, find B such that A X B = Ayi-Axj

2. Relevant equations
I know A X B= ABsin$$\theta$$

3. The attempt at a solution

2. Jul 16, 2008

### Nick89

You have missed the important part:

3. 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 lenght of the vector. Don't forget what a vector is!

3. Jul 16, 2008

### 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 theres no way thats possible. However i don't know how to determine it with 3 different axis.

4. Jul 16, 2008

### D H

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

5. Jul 16, 2008

### 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?