Question

tgx-2ctg+1=0 помогите решить

Answer 1

tg x - 2 ctg x +1=0
ОДЗ sinx≠0 cosx≠0 x≠πn x≠π/2+πk
tg x =t
t - 2/t +1=0
t^2+t-2=0
D=1-4*1*(-2)=9
t12=(-1+-3)/2=-2 1
tg x =1
x= π/4 + πN N∈Z
tg x =-2
x = - arctg 2 + πK K∈Z