Question

помогите

1)sin²38°+cos76°
2)cos82° - cos²41°

Answer 1

sin²38°+cos(2·38°)=sin²38°+cos²38°-sin²38°=cos²38°.

2)=cos(2·41°)-cos²41°=cos²41°-sin²41°-cos²41°=- sin²41°.