Question

what's the Angle between A vector+B vector which in A+B=A-B​?

Answer 1

Answer:

Given:

An Vector Equation has been provided as follows:

A + B = A - B

To find:

Angle between vect. A and vect. B

Calculation:

│A + B│=│A - B│

=> √{A² + B² + 2ABcos(θ)} = √{A² + B² + 2ABcos(180-θ)}

Squaring on both sides:

=>A² + B² + 2ABcos(θ) = A² + B² + 2ABcos(180-θ)

=> 2ABcos(θ) = 2ABcos(180-θ)

=> 2ABcos(θ) = -2ABcos(θ)

=> 4ABcos(θ) = 0

=> cos(θ) = 0

=> θ = 90°

So the vectors are at right angle = 90°