Question

Упростите выражение :

Answer 1

$\frac{Ctg ^{2} t -1 }{Ctgt }* \frac{tg t }{1-tg ^{2} t } -1= \frac{ \frac{1}{tg ^{2}t } -1}{ \frac{1}{tgt} } * \frac{tgt}{1-tg ^{2}t }-1= \frac{1-tg ^{2}t }{tgt}* \frac{tgt}{1-tg ^{2} t}-1=1-1$$=0$