inverse %7B%7B1%2C 1%2C 2%7D%2C %7B-1%2C 2%2C 2%7D%2C %7B3%2C 2%2C 3%7D%7D

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.