Question

Помогите очень срочно нужно, дам 15 баллов
1-cos^2a/sin^2a+1/sin^2a(1+tg^2a)

Answer 1

$\frac{1-Cos^{2}\alpha}{Sin^{2}\alpha}+\frac{1}{Sin^{2}\alpha(1+tg^{2}\alpha)}=\frac{Sin^{2}\alpha}{Sin^{2}\alpha}+\frac{1}{Sin^{2}\alpha*\frac{1}{Cos^{2} \alpha}} =1+\frac{1}{tg^{2}\alpha} =1+Ctg^{2}\alpha=\frac{1}{Sin^{2}\alpha}$