Question

tgx-2ctgx =-1

Answer 1

Тангенс (-63.4349)=-2
ctg(90- @))=tg @.
tg 63.4349=2
ctg (90-63.4349)=2
ctg 26.565=2

Answer 2

tgx-2ctgx=-1 |:ctg x

tg²x-2=-1

tg²x=3

x=arctg √3+πn 

x=π/3+πn