Question

Превратите в произведение и упростите

sin25 + sin 15 / sin 25 -sin 15

Answer 1

( 2 (sin (25+15)/2) * (cos (25-15)/2) ) / ( 2 (sin (25-15)/2)* (cos (25+15)/2))=
=(sin20*cos5) / (sin5*cos20) = tg 20 * ctg 5