(sin^2(9x)-cos^2(9x))(sin^2(9x)+cos^2(9x))=sin4x
-cos18x=sin4x
cos18x+cos(П/2-4x)=0
2cos(7x+П/4)cos(11x-П/4)=0
7x+П/4=П/2+Пk 11x-П/4=П/2+Пk
7x=П/4+Пk 11x=3П/4+Пk
x=П/28+Пk/7 x=3П/44+Пk/11
(sin^2(9x)-cos^2(9x))(sin^2(9x)+cos^2(9x))=sin4x
-cos18x=sin4x
cos18x+cos(П/2-4x)=0
2cos(7x+П/4)cos(11x-П/4)=0
7x+П/4=П/2+Пk 11x-П/4=П/2+Пk
7x=П/4+Пk 11x=3П/4+Пk
x=П/28+Пk/7 x=3П/44+Пk/11