Lösung 3.2:4d
Aus Online Mathematik Brückenkurs 2
(Unterschied zwischen Versionen)
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- | {{ | + | For magnitudes of quotients, we have the arithmetical rule |
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+ | <math>\left| \frac{z}{w} \right|=\frac{\left| z \right|}{\left| w \right|}</math> | ||
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+ | We can therefore take the magnitude of the numerator and denominator separately and then divide the magnitudes by each other: | ||
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+ | <math>\begin{align} | ||
+ | & \left| \frac{3-4i}{3+2i} \right|=\frac{\left| 3-4i \right|}{\left| 3+2i \right|}=\frac{\sqrt{3^{2}+\left( -4 \right)^{2}}}{\sqrt{3^{2}+2^{2}}}=\frac{\sqrt{9+16}}{\sqrt{9+4}} \\ | ||
+ | & =\frac{\sqrt{25}}{\sqrt{13}}=\frac{5}{\sqrt{13}} \\ | ||
+ | \end{align}</math> |
Version vom 15:39, 22. Okt. 2008
For magnitudes of quotients, we have the arithmetical rule
\displaystyle \left| \frac{z}{w} \right|=\frac{\left| z \right|}{\left| w \right|}
We can therefore take the magnitude of the numerator and denominator separately and then divide the magnitudes by each other:
\displaystyle \begin{align}
& \left| \frac{3-4i}{3+2i} \right|=\frac{\left| 3-4i \right|}{\left| 3+2i \right|}=\frac{\sqrt{3^{2}+\left( -4 \right)^{2}}}{\sqrt{3^{2}+2^{2}}}=\frac{\sqrt{9+16}}{\sqrt{9+4}} \\
& =\frac{\sqrt{25}}{\sqrt{13}}=\frac{5}{\sqrt{13}} \\
\end{align}