1) two forces f1, and f2 are given by the vectors f, = (pi+5)) n and f, - (31+q)) n. the
r = fi + f2 acts in a direction which is parallel to the vector 21 - 5j.
a find the angle, to 2 decimal places, between r and the vector 21. (2 marks)
b show that 5p + 2q = -25. (4 marks)
c given that p -3, find, to 2 decimal places, the magnitude of r. (4 marks)