Решите

Question

Решите

Answer 1

1/sin^2 (x) =ctg^2(x)+1
ctg^2(x)+1-ctgx-3=0
ctg^2 (x)-ctg(x)-2=0
(ctg x -2)(ctg x +1)=0
сtg x =-1
x= 3pi/4+pik
ctg x =2
x= arcctg 2 +pik