from sympy import *
from sympy.abc import x
f = x**3 - 3*x + 1
res = solve(f)
print(res)
然而,对于虚数单位,它给出了不正确的答案.判断VIA subs
也不会返回0.
最新版本:
回复:
[-3/((-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)) - (-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)/3,
-(-1/2 + sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)/3 - 3/((-1/2 + sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)),
-(27/2 + 27*sqrt(3)*I/2)**(1/3)/3 - 3/(27/2 + 27*sqrt(3)*I/2)**(1/3)]
Subs判断:
>>> print(f.subs(x, res[0]))
1 + (-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3) + (-3/((-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)) - (-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3)/3)**3 + 9/((-1/2 - sqrt(3)*I/2)*(27/2 + 27*sqrt(3)*I/2)**(1/3))
剧情:
>>> plot(f, xlim=(-2, 2), ylim=(-2, 2))