Hi there all, I've been doing some work to try and keep myself sharp over the holidays but I've reached a point where I'm doing maths I have no notes for, and one particular topic has me completely stuffed - a few more difficult derivatives, primarily between matrices. http://www.dpmms.cam.ac.uk/site2002/Teaching/IB/AnalysisII/2008-2009/08sheet4.pdf [Broken] This is my last worksheet and although I managed to fumble my way through the first 2 parts of Q6, I haven't got a clue how to approach Qns 2, the rest of 6, all of 7, 8, and 10 - i.e. the majority of the questions! I can't find the definition of a derivative for these situations anywhere online, nor for 'continuously differentiable' in cases other than R^n. However much help I can get, even things like just definitions or an example of one of these questions would be really really appreciated, this is the only thing I can't seem to get moving on in all my work so the more assistance I can get the better. Thankyou -very- much in advance!