3. If|u| = 3, ||| = 8 and the angle between these vectors is 83, determine a) uxv [2 marks] b) [2 marks] 20. Given a = [6,-5,1], = [3,5,1] and c = [8,5, 2], find a) [2 marks] b) ax [2 marks] c) 0, the angle between a and c [3 marks] d) projeb [3 marks] e) Are the vectors a, b and c coplanar? Show your answer algebraically. [3 marks]