What is the angle between 3a and -5a? What is the ratio of magnitude of two vectors?

As both the vectors are in the opposite direction of each other therefore, both the vectors are having opposite signs i.e. 3a is positive and -5a is negative, so the difference of angle between them is:=180°Magnitude of the positive vector:=3 aMagnitude of the negative vector:=5 aTherefore, the two vectors ratio is:=3a5a=35=0.6Hence, the ratio of the magnitude of both the vectors is 0.6.