Question

(1+ctgx)^2-1/sin^2 x

Answer 1

1/sin²x-1-ctgx=0
1-1/sin²x=ctg²x
-ctg²x-ctgx=0
ctgx(ctgx+1)=0
ctgx=0
x=π/2+πN
ctgx=-1
x=π/4+πN