Question

Помогите решить!!!!!!!!!

Answer 1

$tg^2t(-1+ \frac{1}{sin^2t } ) = tg^2t\cdot ctg^2t=1^2=1$

Answer 2

Calculation Question

It seems like you have a mathematical expression that you need help solving. Could you please provide the specific expression or equation that you would like assistance with? Once I have that information, I'll do my best to help you solve it.