Question

Как решить уравнение x^3=-x-10

Answer 1

x³ = - x - 10
x³ + x + 10 = 0
(x³ + 8) + (x + 2) = 0
(x³ + 2³) + ( x + 2) = 0
(x + 2)(x² - 2x +4) + (x + 2) = 0
(x + 2)(x² - 2x + 4 + 1) = 0
(x + 2)(x² - 2x + 5) = 0
x + 2 = 0                        x² - 2x + 5 = 0
x = - 2                           D = 4 - 4 * 5 = 4 - 20 = - 16 < 0 - решений нет
Ответ : - 2