# Cross product

1. Oct 9, 2008

### FrankJ777

I have a question about solving a problem involving a cross product. I understand how to find $$\vec{a}$$ X $$\vec{b}$$ = $$\vec{c}$$, but if $$\vec{a}$$ and $$\vec{c}$$ are given how do I find $$\vec{b}$$? Is there something I can do analogous to c/a =b? I've been reviewing my old calc III and linear algebra notes, but I havn't been able to figure it out. Any help would be most appreciated.

Thanks

2. Oct 9, 2008

### Ben Niehoff

Given a and c, there are several possible vectors b such that a x b = c. They all lie in the plane perpendicular to c.

3. Oct 10, 2008

### sutupidmath

do you know how to find a vector that is perpendicular to another vector?

4. Oct 19, 2008

### chota

a x c = b

since b is a vector that is perpendicular to both a and c .. :-D