2cos37cos23-sin76

2cos37cos23-sin76

Ответ:

2cos37cos23-sin76=2*(1/2)*(cos(37-23)+cos(37+23))-sin76=

=cos14+cos60-sin76=cos14-sin76+1/2=cos14-sin(90-14)+1/2=cos14-cos14+1/2=1/2

Источник: https://znanija.com/task/177276