Решите уровнение cos(x/2+π/4)+1=0
Cos(x/2+π/4)+1=0 cos(x/2+π/4)=-1 x/2+π/4=π x/2=π-π/4 x/2=3π/4 x=3π/2 + 2kπ, k∈Z ================ (cosπ=-1)