3+cosx=3tgx/2 3(1-tgx/2)+cosx=0 3(1-tgx/2)+(1-tg^2(x/2))(1+tg^2(x/2))=0 (1-tg^x/2)(3+(1+tgx/2)/(1+tg^2(x/2))=0 1)1-tgx/2=0;tgx/2=1;x/2=π/4+πk;x=π/2+2πk 2)3+3tg^2(x/2)+1+tgx/2=0;(1+tg^2(x/2)#0) tgx/2=t 3t^2+t+4=0 D=1-48<0 нет решения ответ π/2+2πk;k€Z
3(1-tgx/2)+cosx=0
3(1-tgx/2)+(1-tg^2(x/2))(1+tg^2(x/2))=0
(1-tg^x/2)(3+(1+tgx/2)/(1+tg^2(x/2))=0
1)1-tgx/2=0;tgx/2=1;x/2=π/4+πk;x=π/2+2πk
2)3+3tg^2(x/2)+1+tgx/2=0;(1+tg^2(x/2)#0)
tgx/2=t
3t^2+t+4=0
D=1-48<0
нет решения
ответ π/2+2πk;k€Z