Math Forum http://mathforum.org/kb List of forum topics en finding the local derivative http://mathforum.org/kb/thread.jspa?messageID=8254373&tstart=0#8254373
I came across this thread Feb 6, 2013 8:08:08 AM Feb 6, 2013 8:08:08 AM 591781@swansea.ac.uk 0