in the external division formula the denominator is m-n ....bt suppose the ratio m/n equals 1 ===> m=n ...then the section formula for external division gives a vector that have infinite direction ratios... how to deal with this plz explain . amen...:)
The explanation of the mentioned concept is explained in the following link:
Class 12 → NCERT → Math → Part 2 → Chapter 10 → Vector Algebra → Page Number 439
Below mentioned is the snapshot of the same link. Please go through it.