a) D∈R 7x - 9 = 0 7x = 9 x = ⁹/₇ b) D∈R -x²+4x -3 = 0 Δ = 16 - 12 = 4 √Δ = 2 x₁=(-4-2)*(-¹/₂) = 6/2 = 3 x₂ = (-4+2)*(-¹/₂) = 2/2 = 1 c)D∈R (x-2)² = 0 x-2 = 0 x = 2 d) x+6 ≠0 x = ≠-6 D∈R/{-6} x-3 = 0 x = 3 f) x-6≠0 x≠6 D∈R/{6} x²-36 = 0 (x-6)(x+6) = 0 x = 6 ∨ x = -6 6 nienalezy do dziedziny
a) f(x) = 7x - 9 D : x ∈ R 7x - 9 = 0 I + 9 7x = 9 I : 7 x = 1 2/7 f(x) = 0 ⇔ x = 1 2/7 b) f(x) = -x² + 4x - 3 D : x ∈ R -x² + 4x - 3 = 0 I * (-1) x² - 4x + 3 = 0 x² - x - 3x + 3 = 0 x(x - 1) - 3(x - 1) = 0 (x - 3)(x - 1) = 0 x = 3 lub x = 1 f(x) = 0 ⇔ x = 3 lub x = 1 c) f(x) = (x - 2)² x ∈ R (x - 2)² = 0 I √ x - 2 = 0 I + 2 x = 2 f(x) = 0 ⇔ x = 2 d) f(x) = (x - 3) / (x + 6) x + 6 ≠ 0 x ≠ -6 D : x ∈ R {-6} (x - 3) / (x + 6) = 0 I * (x + 6) x - 3 = 0 + 3 x = 3 ∈ D f) f(x) = (x² - 36) / (x - 6) x - 6 ≠ 0 + 6 x ≠ 6 D : x ∈ R {6} (x² - 36) / (x - 6) = 0 [(x - 6)(x + 6)] / (x - 6) = 0 x + 6 = 0 I - 6 x = -6 ∈ D
