Sir, Could you please explain for finding the feasible region in minimising costs question, why is the feasible region away from the origin? And also can we be asked to draw the graph in the exam for the paper version? Thank you.
The feasible region is away from the origin because the constraints are ‘more than’ constraints. For example, maybe they must use at least 1,000 kg of material.
It is now very unlikely that you will be asked to draw a graph – even in the paper based exam – but you can certainly be expected to prove that you understand a graph already drawn for you in the question. For that reason it is vital that you are able to draw it yourself – only then can you be certain that you really do understand it.