Question

Подскажите пож в тригонометрии

Sin5n/6 * cos5n/7 * tg5n/8 * ctg5n/9

Answer 1

Sin5n/6 * cos5n/7 * tg5n/8 * ctg5n/9=sin(n-1п/6)*cos(n-2п/7)*tg(n-3п/8)*ctg(n-4п/9)=

=sinп/|6*cos2п/7*tg3п/8*ctg4п/9=1/2*cos2п/7*tg3п/8*ctg4п/9