Вычислите: a] sin 15° b] cos88° cos2° - sin88° - вопрос №5677415882882505 от MrLeysanHD 27.02.2020 18:32

Question

Алгебра: Вычислите: a] sin 15° b] cos88° cos2° - sin88° sin2° c] sin50° cos5° - cos50° sin5°

MrLeysanHD · Answer

a) sin15*=sin(45-30)=sin45*cos30* - cos45*sin30= sqrt(2)/2 * sqrt(3)/2 - sqrt(2)/2* 1/2= sqrt(2) (sqrt(3)-1))/4   b) cos(88+2)=cos(90*)=0 c) sin(50-5)=sin(45*)=sqrt(2)/2 ...