.7 Given that the position vectors of points T and S are 4a, + 6a, -a, and 10a, + 12a, + 8a, respectively, find: (a) the coordinates of T and S, (b) the distance vector from 1 to S, (c) the distance between T and S. 1.11 Given that 1.12 If A = 4a, P = 2a, -a, - 2a. Q = 4a, + 3a, + 2a. R=- + ay + 2a find: (a) P+Q-R, (b) P (e) (PXQ) X (QX R), (f) cos - QX R, (c) QX P R. (d) (PXQ) (Q X R), pr. (g) sin po PR = 6a, + a, and B 2a, + 5a,, find: (a) A B +2|B|² (b) a unit vector perpendicular to both A and B 1.17 Points P, Q, and R are located at (-1, 4, 8), (2, -1, 3), and (-1, 2, 3), respectively. Determine (a) the distance between P and Q, (b) the distance vector from P to R, (c) the angle between QP and QR, (d) the area of triangle PQR, (e) the perimeter of triangle PQR.