Question 4 [50 marks] Consider the following vectors a =71 - j-k b =-3i - } c=-i-5k i) Find 2c +a. (10 marks) ii) Find the unit vector b (b) . (10 marks) iii) Find the modulus of vector a. (10 marks) iv) Find the dot product of a and c. (10 marks) V) Find the angle between a and c in radians. (10 marks)