Answer:
The sum of vectors P and Q is given by the vector R, the resultant sum vector using the parallelogram law of vector addition. If the resultant vector R makes an angle ϕ with the vector P, then the formulas for its magnitude and direction are: |R| = √(P2 + Q2 + 2PQ cos θ) β = tan-1[(Q sin θ)/(P + Q cos θ)]