2 tg x - ctgx + 1=0 решить уравнение

2tg (x) - ctg (x) + 1=0

2tg (x) - 1/tg (x) + 1=0

tg (x) = t

2t-1/t + 1=0

2t^2-1+t=0

2t^2+t-1=0

D=b^2-4ac=9

t1,2 = (-b±√D) / 2a

t1 = (-b+√D) / 2a = (-1+3) / 4=0,5

t2 = (-b+√D) / 2a = (-1-3) / 4=-1

a) tg (x) = 0,5=> x=arctg (0,5) + pi*n

б) tg (x) = - 1 = > x=arctg (-1) + pi*n=> x=3pi/4 + pi*n