If a, b, and c are vectors, and a=b x c, and a and c are known, how do I solve for b? b=a/c ? I don't think we've covered diving vectors, and since the cross-product is a special case of multiplying vectors (as opposed to dot product), I'm not sure this is allowed anyway. I'm trying to compute dipole moment, given a torque and an electric field. In my above example, a is torque, and c is electric field. I need to solve for b. Thanks!