根号2/4 sin(45°-x）+根号6/4 cos(45°-x)
=根号2/2[1/2 cos(45°-x）+（根号3）/2 sin(45°-x)]/2sin(90°-2x）
=根号2/2[sin30°cos(45°-x）+cos30°sin(45°-x)]
=根号2/2sin(75°-x)