Question

sin(3π/2+x)tg(π/2+y)/cos(π-x)ctg(3π-y)-sin(7π-y)ctg(5π/2+x)/cos(2π-y)tg(11π-x)

Answer 1

по формулам превидения
ост. cosx*ctgy/-cosx*ctgy-siny*tgx/-cosy*tgx=tgy-1