1. If 1, 72, and 3 are noncoplanar vectors, let J2 X V3 V3 X V1 V1 (J2 X V3) U1(V2 X U3
V1 X T2
U1:(V2 X V3)
(These vectors occur in the study of crystallography. Vectors of the form n10i + n202 + n333, where each ni is an integer, form a lattice for a crystal Vectors written similarly in terms of k1, k2, k3: form the reciprocal lattice.) (a) Show that ki is perpendicular to 1; if i # j. (b) Show that ki.yi=1 for i=1,2,3.