Proof Parallelogram Law
Consider two vectors P and Q with an angle θ between them. 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 angleϕwith 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)]
Let us first see the statement of the...