(ctgx+tgx)(ctgx-tgx)=4(ctgx-tgx)
tgx=ctgx
sin^2x-cos^2x=0
-cos2x=0
x=П/4+Пk/2
ctgx+tgx=4
sin^2x+cos^2x=4sinxcosx
1/2=sin2x
2x=(-1)^kП/6+пk
x=(-1)^kП/12+Пk/2
(ctgx+tgx)(ctgx-tgx)=4(ctgx-tgx)
tgx=ctgx
sin^2x-cos^2x=0
-cos2x=0
x=П/4+Пk/2
ctgx+tgx=4
sin^2x+cos^2x=4sinxcosx
1/2=sin2x
2x=(-1)^kП/6+пk
x=(-1)^kП/12+Пk/2