题目
求z^4=sqrt(3)+i的根.
求$z^{4}=\sqrt{3}+i$的根.
题目解答
答案
将复数 $\sqrt{3} + i$ 转化为极坐标形式,得 $r = 2$,$\theta = \frac{\pi}{6}$。
方程 $z^4 = 2\left(\cos\frac{\pi}{6} + i\sin\frac{\pi}{6}\right)$ 的解为:
\[
z_k = \sqrt[4]{2} \left( \cos\left(\frac{\pi}{24} + \frac{k\pi}{2}\right) + i\sin\left(\frac{\pi}{24} + \frac{k\pi}{2}\right) \right), \quad k = 0, 1, 2, 3
\]
具体解为:
\[
\boxed{
\begin{array}{ll}
z_0 = \sqrt[4]{2} \left( \cos\frac{\pi}{24} + i\sin\frac{\pi}{24} \right), \\
z_1 = \sqrt[4]{2} \left( \cos\frac{13\pi}{24} + i\sin\frac{13\pi}{24} \right), \\
z_2 = \sqrt[4]{2} \left( \cos\frac{25\pi}{24} + i\sin\frac{25\pi}{24} \right), \\
z_3 = \sqrt[4]{2} \left( \cos\frac{37\pi}{24} + i\sin\frac{37\pi}{24} \right).
\end{array}
}
\]
或等价表示为:
\[
\boxed{
\sqrt[4]{2} e^{i\frac{\pi}{24}}, \sqrt[4]{2} e^{i\frac{13\pi}{24}}, \sqrt[4]{2} e^{i\frac{25\pi}{24}}, \sqrt[4]{2} e^{i\frac{37\pi}{24}}
}
\]