Ctg2 2x - 6 ctg 2x + 5 = 0

Question

Ctg2 2x - 6 ctg 2x + 5 = 0

Answer 1

ctg22x – 6ctg2x +5=0

Обозначим ctg2x=у

у2-6у+5=0

Д=36-20=16

У=5

У=1

 

                     ctg2x=5,   ctg2x=1

                                    х=0,5arcctg5+0,5Пп

                     х=arcctg1+Пn=П/8+0,5п