If a = [1, 2, 3] and b = [1, 3, -2], find the angle between a and b. a. 85.90 C. 450 b. 90 d. 60 If |u'|= 63, |v)= 47, and the angle between u and v is 180, find |proj; ul. a. 47 C. 63~/2 b. 2961 d. 63