sin375°sin105°-4(cos22°30')^2
=sin(360°+15°)sin(90°+15°)-2(cos45°+1)
=sin15°cos15°-2cos45°-2
=(1/2)sin30°-√2-2
=1/4-√2-2
=-7/4-√2
sin375°sin105°-4(cos22°30')^2
=sin(360°+15°)sin(90°+15°)-2(cos45°+1)
=sin15°cos15°-2cos45°-2
=(1/2)sin30°-√2-2
=1/4-√2-2
=-7/4-√2