In this post we take a look at finding the points on a line which has a specific distance away from another point. The "hence" part of this question is actually a thinking question in which the solution is very simple if a student catches the link from the previous part.
A level has been kind to allow for "otherwise" method which is much longer and is what many "model" answers used online. This question can be used to identify whether a student is a "thinking" student or one who do things by "brute force". Due to copyright issues, the question below has been modified but the original essence of the question remains the same.