Sin(11π/12) × cos(5π/12)

`sin ((11\pi)/12) . cos ((5\pi)/12)`

`= (\sqrt{6} - \sqrt{2})/4 . (\sqrt{6} - \sqrt{2})/4`

`= ((\sqrt{6} - \sqrt{2})^2)/16`

`= (6 - 2\sqrt{12} + 2)/16`

`= (2 - \sqrt{3})/4`