xoma
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1 месяц назад
√(4x^2 - 3x - 1) = x + 1;
{x + 1 ≥ 0;
{4x^2 - 3x - 1 = (x + 1)^2;
{x ≥ -1;
{4x^2 - 3x - 1 = x^2 + 2x + 1;
{x ∈ [-1; ∞);
{3x^2 - 5x - 2 = 0;
D = 5^2 + 4 * 3 * 2 = 49 = 7^2;
x = (5 ± 7)/6;
x1 = (5 - 7)/6 = -2/6 = -1/3 ∈ [-1; ∞);
x2 = (5 + 7)/6 = 12/6 = 2 ∈ [-1; ∞).