tgx-2ctgx =-1
Тангенс (-63.4349)=-2 ctg(90- @))=tg @. tg 63.4349=2 ctg (90-63.4349)=2 ctg 26.565=2
tgx-2ctgx=-1 |:ctg x
tg²x-2=-1
tg²x=3
x=arctg √3+πn
x=π/3+πn