Question

(tg^2a-sin^2a)*ctg^2a/sin^2a =1 Доказать тождество

Answer 1

Ответ:

(tg^2 a-sin^2 a) * ctg^2 a=sin^2 a

(tga*ctga) ^2-sin^2 a*cos^2a/sin^2a

=1-cos^2 a=sin^2 a

sin^2 a=sin^2 a