Упростите (sin п/12+sin 7П/12)/ (Sin 5П/12 - cos 5П12)

(sin(п/2 - 5п/12)+sin(п-5п/12))/ (Sin 5П/12 - cos 5П12) = (cos 5п/12 - sin 5п/12)/ (Sin 5П/12 - cos 5П12) = - 1