Помогите решить!!!! 1. 3sin^2(2x)+7cos(2x)=3 2. cos^4(x/2)-cos^2(x/2)=0 3. ctg(3x/2)=1/√3 4. 1-ctg(4x-4pi)=0 5. ctg(4pi/√x)=-√3

1.[latex]3sin ^{2} 2x+7cos2x=3[/latex] ОДЗ: x∈R [latex]3sin ^{2}2x+7cos2x-3=0[/latex] [latex]3sin ^{2} 2x+7cos2x-3cos ^{2} 2x-3sin ^{2} 2x=0[/latex] [latex]-3cos ^{2} 2x+7cos2x=0[/latex] [latex]cos2x(3cos2x+7)=0[/latex] [[latex]cos2x=0[/latex] ;            [x=[latex] \pi /4+ \pi n/2; n[/latex]∈Z [[latex]3cos2x+7=0[/latex];       [x=[latex] \pi -arccos7/3+ \pi n;[/latex] n∈Z 2. cos^4(x/2)-cos^2(x/2)=0 ОДЗ: х∈R [latex]cos ^{2} x/2(cos ^{2} x/2-1)=0[/latex] cos²x/2=0;    1+сosx/2=0;  x= П+2Пn; n∈Z cos²x/2=1;  1+сosx/2=1;    x=2Пn; n∈Z 3. ctg(3x/2)=1/√3 ОДЗ:х≠2Пn/3;n∈Z 3х/2=П/3+Пn; n∈Z 3x=2П/3+2Пn; n∈Z х=2П/9+2Пn/3; n∈Z 4.1-ctg(4x-4pi)=0 ОДЗ: x≠5Пn/4;n∈Z 1+ctg4x=0 4х= -П/4+Пn;n∈Z х= -П/16+Пn/4;n∈Z