Question

3. R is the resultant of P and Q. If P = 4 units,
Q = 5 units and R = 6 units, find the angle
between P and Q.
(2 marks)​

Answer 1

Answer:

R² = P² + Q² + 2PQ Cos©

36 = 16 + 25 + 2*4*5 Cos©

-5 = 40 Cos©

Cos© = -1/8

Angle = arc cos (-1/8)