2cos(3x-П/4)=-1
cos(3x-П/4)=-1/2
3x-П/4=+ - 2/3П+2Пn
3x=2/3п+П/4+2Пn=11/12П+2Пn,
х=11/36П+2/3Пn
3x-П/4= - 2/3П+2Пn,3x=-2/3п+П/4+2Пn=-5/12П+2Пn,
х=-5/36П+2/3Пn
2cos(3x-П/4)=-1
cos(3x-П/4)=-1/2
3x-П/4=+ - 2/3П+2Пn
3x=2/3п+П/4+2Пn=11/12П+2Пn,
х=11/36П+2/3Пn
3x-П/4= - 2/3П+2Пn,3x=-2/3п+П/4+2Пn=-5/12П+2Пn,
х=-5/36П+2/3Пn