determinant(-a-l,a,0,0,a,-a-2b-l,b,b,0,b,-b-l,0,0,b,0,-b-l)

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.