1) 4cos a/4 cos 2n+a/2 2) 1/ 1-tga - 1/1+tga 3) (sina/1+cosa - вопрос №41002081442221111311 от VETALmc005 25.03.2020 15:50

Question

Математика: 1) 4cos a/4 cos 2n+a/2 2) 1/ 1-tga - 1/1+tga 3) (sina/1+cosa + sina/1-cosa) sin2a

VETALmc005 · Answer

1/ (1-tga )- 1/(1+tga)=(1+yga-1+tga)/(1-tg²a)=2tga/(1-tg²a)=tg2a(sina/1+cosa + sina/1-cosa) sin2a=[sina(1-cosa+1+cosa)]*sin2a/(1-cos²a)==2sina*2sinacosa/sin²a=4cosa...