解一元二次方程
x = 5 (cos120 +- i sin120).
x^3 = 125(cos 360 +- i sin 360) = 125.
解一元二次方程
x = 5 (cos120 +- i sin120).
x^3 = 125(cos 360 +- i sin 360) = 125.
• X^3 = 125 -> X=5 -> x^2 + 5x + 25 == 25 + 25 + 25 = 0. -2022_2092- ♂ (0 bytes) () 02/02/2023 postreply 11:10:17