2sin²x - 2sinx - 1 = 0
Пусть sinx = t, тогда
2t² - 2t - 1 = 0
D = 4 + 8 = 12
√D = 2√3
t₁ = ( 1 + √3)/2
t₂ = ( 1 - √3)/2
1) sinx = (1+√3)/2
Корней нет
2) sinx = (1-√3)/2
<span>x = ( -1)^n* arcsin((1-</span>√<span>3)/2) + </span>π<span>n, n</span>∈<span>Z</span>
Х : 7\18 = 2\3 * 9\7
х : 7\18= 6\7
х = 6\7 * 7\18
х = 1\3
Ответ: 5a gdrjcdhcfjjddrtgg