The candidates think that this is the best way to increase their speed of solving questions. But, it’s not actually. Clarity of concept is the best way to increase the speed of question solving. Learning up excessive formulae and shortcuts means that during the actual exam you have to recall the formula correctly and then solve the question. This takes almost an equivalent amount of time if not more.
Also, there is risk of making mistakes due to incorrect formula, because a candidate has to learn a lot of formulae that are more often than not, very case to case dependent. There is a high probability that the candidate might recall/use an incorrect formula under the exam time stress.
Even when learning up these shortcuts and formulae is easy, there is no guarantee that you would be accurate in the application of these formulae. There might be a mismatch in the formula used and the question type.
A lot many times when a candidate fails to remember or recall the correct formula or when there is even the slightest of doubts, they panic. Because they have not been conditioned to start from the basics, they are not even able to derive the correct formula and instead end up panicking and wasting their precious time.
Rote learning versus conceptual understanding is the dilemma candidates should get rid of. Inclination towards shortcuts, promotes rote learning and not conceptual clarity. No matter what higher education program you land up in, lack of conceptual clarity would always come back to haunt you and then the number of formulae you had learnt up would be of no help.