絶対値の冪乗
絶対値の冪乗
\[ \left|\alpha^{b}\right|=\left|\alpha\right|^{b} \]
\begin{align*} \left(\left|\alpha\right|^{b}\right)^{\gamma} & =\left|\alpha\right|^{b\gamma} \end{align*}
(1)
\[ \left(\left|\alpha\right|\beta\right)^{\gamma}=\left|\alpha\right|^{\gamma}\beta^{\gamma} \](2)
\[ \alpha^{\beta}=\left|\alpha\right|^{\beta}\sgn^{\beta}\left(\alpha\right) \](3)
\(b\in\mathbb{R}\)とする。\[ \left|\alpha^{b}\right|=\left|\alpha\right|^{b} \]
(4)
\(b\in\mathbb{R}\)とする。\begin{align*} \left(\left|\alpha\right|^{b}\right)^{\gamma} & =\left|\alpha\right|^{b\gamma} \end{align*}
(1)
\begin{align*} \left(\left|\alpha\right|\beta\right)^{\gamma} & =e^{\gamma\Log\left(\left|\alpha\right|\beta\right)}\\ & =e^{\gamma\left(\ln\left|\alpha\right|+\Log\beta\right)}\\ & =\left|\alpha\right|^{\gamma}\beta^{\gamma} \end{align*}(2)
\begin{align*} \alpha^{\beta} & =\left(\left|\alpha\right|\sgn\alpha\right)^{\beta}\\ & =\left|\alpha\right|^{\beta}\sgn^{\beta}\left(\alpha\right) \end{align*}(3)
\[ \begin{align*}\left|\alpha^{b}\right| & =\left|e^{b\Log\alpha}\right|\\ & =\left|e^{b\left(\Log\left|\alpha\right|+i\Arg\left(\alpha\right)\right)}\right|\\ & =\left|\left|\alpha\right|^{b}e^{ib\arg\alpha}\right|\\ & =\left|\left|\alpha\right|^{b}\right|\left|e^{ib\arg\alpha}\right|\\ & =\left|\alpha\right|^{b} \end{align*} \](4)
\begin{align*} \left(\left|\alpha\right|^{b}\right)^{\gamma} & =e^{\gamma\Log\left|\alpha\right|^{b}}\\ & =e^{\gamma b\ln\left|\alpha\right|}\\ & =\left|\alpha\right|^{b\gamma} \end{align*}
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| タイトル | 絶対値の冪乗 |
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2乗のルート
\[
\sqrt{\alpha^{2}}=\left|\alpha\right|\sqrt{\sgn^{2}\left(\alpha\right)}
\]
偏角・対数の和と差
\[
\Arg\alpha+\Arg\beta=\Arg\left(\alpha\beta\right)+2\pi\mzp_{-1,0}\left(-\pi,\pi;\Arg\alpha+\Arg\beta\right)
\]
複素数と複素共役の和・差
\[
z\pm\overline{z}=2H\left(\pm1\right)\Re z+2iH\left(\mp1\right)\Im z
\]
冪乗の性質
\[
\pv\alpha^{\beta}\pv\alpha^{\gamma}=\pv\alpha^{\beta+\gamma}
\]