Докажите тождество (tg) ^2 a - (sin) ^2 a = (sin) ^2 a (tg) ^2 a

Tg²a - sin²a = sin²a * tg²a

sin²a/cos²a - sin²a = sin²a * tg²a

sin²a * (1/cos²a - 1) = sin²a * tg²a

sin²a * ((1-cos²a) / cos²a) = sin²a*tg²a

sin²a * (sin²a/cos²a) = sin²a * tg²a

sin²a * tg²a = sin²a * tg²a