What is the Negative of a Vector?

Answer: A vector’s negative is another vector that can be created by multiplying it by -1. In other words, the vector -a is the opposite of a. In this case, however, a and -a are in opposition despite having equal amplitudes. That is, a and -a point in different directions, therefore |a| = |-a| 

If the vector AB is from A to B, then the vector BA, which is the vector’s opposite, is from B to A. To put it another way, the vector’s direction changes simply by multiplying by a negative sign. We can then state that AB = – BA and BA = – AB. Moreover, |AB| = |BA|. As a result, AB and BA are the opposites of one another.