Will
Does anyone know of any sites that have original textbook like problems for math/physics/chemistry that one could do? I seem to be running out of problems in my text, some of these that I have done more than a few times, its like I am not really doing them anymore, I just recognize the numbers I got before! So I need new ones. Right now I need something with elementary differential equations, but any site containing problems for the above mentioned subjects would be great.