1. The problem statement, all variables and given/known data Given the vectors: V1=(3,1,2) and V2=(2,2,-1), find the set of vectors which are coplanar with V1 and V2 and also perpendicular to V3=(-2,1,1). Then Find the members of this set which have length 2-Root-11 2. Relevant equations Dot and cross product 3. The attempt at a solution well, a set of vectors coplanar to v1 and v2 would be V = (x,y,z) = (x',y',z') + rV1 +sV2 and a vector perpendicular to v3 in the set of vectors coplanar with v1 and v2 is: V X V3. But what do i do with the 2-root-11?