For example, last june there were some really odd/different questions for C3 that, whilst being on the syllabus, were just very different to how they've ever been worded before. You could have gone through every past paper and read the edexcel books cover to cover and not come across anything like several of the questions there, so what is the best way to prepare/tackle these different questions?
Another example is in C4 where you were expected to be able to integrate 2^t as 2^t/ln2 which is not covered in the textbooks etc.
It seems like a lot of these harder questions are aimed at people simply with better mathematical intuition than those who have just practiced it a lot. So how is somebody with naturally average mathematical intuition supposed to practice for these harder and differently worded exam questions?
e.g. june 2013 expected you to know sinx=cos(x-90) when i've never even come across that before in any papers from C1-4 or even at GCSE, so how is the average student meant to prepare for questions like that? or are they put in there to separate the naturally intuitive from the average students that have just worked hard through the syllabus