**Solved Problems In Mathematics** appears to be a new mathematics blog. It’s a few posts old, but I’m charmed by it. Each post takes some problem and shows how to solve it. It’s been heavy on calculus so far. Many limits, a bunch of evaluate-the-integral problems, and so on. But it may be a good bit of reading if you want to brush up on stuff you once knew, like how to calculate the length of peculiar curves. Or if you have a calculus problem you need to solve and haven’t got any idea what to do. A similar problem may give you a good hint.

Less generally, John Quintanilla’s **Mean Green Math** has looked at one specific calculus problem, a limit, in several different ways. He’s grouped the essays about that together. Most mathematics problems, once you’re away from the cutting edge of human knowledge, have many different possible solutions. Here’s an example of such.

And, what the heck. **Math With Bad Drawings** hardly needs my publicity. But a recent post discusses the challenge of saying just what mathematics is. The comments get into some decent discussion about what mathematics is. And I’m not sure what mathematics is. There are many facets which seem barely to have anything to do with one another; but they do all *feel* related in some way. It’s hard to say just what unites all this.