ctg3x=tg8x
tg8x=1/tg3x
tg3x*tg8x=1
(sin8xsin3x)/(cos8x*cos3x)=1
cos8xcos3x-sin8xsin3x=0
cos(8x-3x)=0
cos5x=0
x=П/10+Пk/5
ctg3x=tg8x
tg8x=1/tg3x
tg3x*tg8x=1
(sin8xsin3x)/(cos8x*cos3x)=1
cos8xcos3x-sin8xsin3x=0
cos(8x-3x)=0
cos5x=0
x=П/10+Пk/5