1. The problem statement, all variables and given/known data Suppose n is normal to a plane and v is parallel to the plane. Describe how you would find a vector u that is both perpendicular to v and parallel to the plane. 2. Relevant equations Cross product, dot product 3. The attempt at a solution Since u is perpendicular to v, u dot v = 0. U is also parallel to the plane so u will be perpendicular to n, so u dot n=0. How would I do the rest of it ?