Many of you will probably already be aware of a couple of the web’s most useful mathematical resources, but in case you’re not, here they are. Both are provided by Stephen Wolfram’s Wolfram Research, who are the manufacturers of Mathematica, one of the three leading computer algebra systems. (So this doesn’t sound too much like an advert: the other two are Maple, which you may have met during your degree course, and the free open-source system Sage.)
Wolfram MathWorld is an online encyclopedia of mathematical topics, regularly updated and with good references to the published literature. It generally gives a more scholarly presentation than Wikipedia, as well as covering more obscure topics. The “random entry” button is also a good way of wasting half an hour while convincing yourself you’re doing maths.
Wolfram Alpha describes itself as a “computational knowledge engine”. It’s like a cross between a search engine and an online computer algebra system. Handy for evaluating those awkward integrals, and you have to admire a piece of software that can recognise classic sci-fi references from Isaac Asimov and Douglas Adams. (Oh, and Stanley Kubrick…)