Question

Срочно помогите решить уравнение 9

Answer 1

9.
(2sinxcosx)/(-cosx) = 1
-2sinx=1
sinx= - ¹/₂
x=(-1)ⁿ⁺¹ π/6 + πk, k∈Z

[3π/4; 9π/4]=[9π/12; 27π/12]

k=1       x=(-1)² π/6 + π= π/6 + π = 7π/6 = 14π/12

k=2       x=(-1)³ π/6 + 2π = -π/6 + 2π = 11π/6 = 22π/12

Ответ: 7π/6;  11π/6.