sin4x<1/8
П-arcsin1/8+2Пk<4x<2П+arcsin1/8+2Пk
П(2k+1)/4-1/4arcsin1/8<x<П/2(1+k)+1/4arcsin1/8
sin^23x<3/4
sinx<sqrt(3)/2
2/3П+2Пk<x<7П/32Пk
sinx>-sqrt(3)/2
2/3П+2Пk<x<4П/3+2Пk
U
5П/3+2Пk<x<7П/32Пk
sin4x<1/8
П-arcsin1/8+2Пk<4x<2П+arcsin1/8+2Пk
П(2k+1)/4-1/4arcsin1/8<x<П/2(1+k)+1/4arcsin1/8
sin^23x<3/4
sinx<sqrt(3)/2
2/3П+2Пk<x<7П/32Пk
sinx>-sqrt(3)/2
2/3П+2Пk<x<4П/3+2Пk
U
5П/3+2Пk<x<7П/32Пk