Tg(пи:4-x:2)= -1 ( в знаке деления " : ",это дробь)
Tg(π/4-x/2)=-1 ctg(x/2+π/4)=-1 x/2+π/4=3π/4+πn x/2=-π/4+3π/4+πn x/2=π/2+πn x=π+2πn,n∈z