Odpowiedź :
x[tex]^{4}[/tex] - 8x² + 7 = 0
Δ = b² - 4ac = (-8)² - 4 × 1 × 7 = 64 - 28 = 36
√Δ = 6
x1 = -b - √Δ / 2a = -(-8) - 6 / 2 = 8 - 6 / 2 = 2 / 2 = 1 - w formie ułamków
x2 = -b + √Δ / 2a = -(-8) + 6 / 2 = 8 + 6 / 2 = 14 / 2 = 7
x ∈ {1,7}
x[tex]^{4}[/tex] - 8x² + 7 = 0
Δ = b² - 4ac = (-8)² - 4 × 1 × 7 = 64 - 28 = 36
√Δ = 6
x1 = -b - √Δ / 2a = -(-8) - 6 / 2 = 8 - 6 / 2 = 2 / 2 = 1 - w formie ułamków
x2 = -b + √Δ / 2a = -(-8) + 6 / 2 = 8 + 6 / 2 = 14 / 2 = 7
x ∈ {1,7}