Question

(sin^2 a+tg^2 a sin^2 a) ctg

 

момогите с решением нубику...

Answer 1

(sin²a+tg²a * sin²a)*ctg

sin²a(1+tg²a)*ctg

sin²a(1/cos²a)*ctg

sin²a*cosa/cos²a*sina

sina/cosa

tga

Answer 2

$(sin^{2}alpha+tg^{2}alpha*sin^{2}alpha)*ctgalpha=sin^{2}alpha*(1+tg^{2}alpha)*ctgalpha=$$sin^{2}alpha*frac{1}{cos^{2}alpha}*ctgalpha=frac{sinalpha}{cosalpha}=tgalpha$