What is law of parallelogram of vector addition? If vector P and vector Q are acting at a angle and their magnitudes are same,

Question

What is law of parallelogram of vector addition? If \(\vec{P}\) and \(\vec{Q}\) are acting at a angle and their magnitudes are same, then prove that resultant \(R = 2P\ cos\frac{\alpha}{2}\)

Answer 1

The multiplication of a vector by a real number either leaves the direction unchanged if the number is positive or reverses the direction. If the number is negative, while the magnitude of the vector is scaled by the magnitude of the number.