找到复杂函数具有实值的点

Finding the points where a complex function is real-valued

我定义了以下复杂系统:

syms x 
sys(x) = ((10+1.*i.*x))/(20+(5.*i.*x)+((10.*i.*x).^2))+((1.*i.*x).^3); 
ImaginaryPart = imag(sys)

MATLAB 返回了以下结果:

ImaginaryPart(x) =

- real(x^3) + imag((10 + x*1i)/(- 100*x^2 + x*5i + 20))


RealPart(x) =

- real(x^3) + imag((10 + x*1i)/(- 100*x^2 + x*5i + 20))

现在 x 的哪个值 ImaginaryPart(x) 会是 0? (即 ImaginaryPart(x)= 0)?

因为 , solve 会为您解决问题:

S = solve(ImaginaryPart(x)== 0,x);