Plot[Sin[x*Sqrt(2)/2-y*Sqrt(2)/2]<Sin[xSqrt(2)/2+y*Sqrt(2)/2],{x,-9/Sqrt(2)*Pi,7/Sqrt(2)*Pi},{y,-8/Sqrt(2)*Pi,8/Sqrt(2)*Pi}]

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.