Question

Решите уравнение 4cos^2(x)-4cos(x)+1=0

Answer 1

4cos^2(x)-4cos(x)+1=0

(2cos(x) - 1)²=0

2cos(x) - 1 =0

cos(x) = 1/2

х= ± π/3 +2ππn  n∈Z