Question

$frac{1+tga+tg^2a}{1+ctga+ctg^2a} =$

Answer 1

(1+sina/cosa+sin²a/cos²a):(1+cosa/sina+cos²a/sin²a)=
=(cos²a+sinacosa+sin²a)/cos²a : (sin²a+cosasina+cos²a)/sin²a=
=(cos²a+sinacosa+sin²a)/cos²a * sin²a/(sin²a+cosasina+cos²a)=
sin²a/cos²a=tg²a