Lösung 3.1:6a
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
K (Lösning 3.1:6a moved to Solution 3.1:6a: Robot: moved page) |
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- | { | + | We use the standard method and augment the fraction with the conjugate of the denominator |
- | < | + | <math>\sqrt{5}+2</math>. Then the conjugate rule gives |
- | {{ | + | |
+ | |||
+ | <math>\begin{align} | ||
+ | & \frac{\sqrt{2}+3}{\sqrt{5}-2}=\frac{\sqrt{2}+3}{\sqrt{5}-2}\centerdot \frac{\sqrt{5}+2}{\sqrt{5}+2}=\frac{\left( \sqrt{2}+3 \right)\left( \sqrt{5}+2 \right)}{\left( \sqrt{5} \right)^{2}-2^{2}} \\ | ||
+ | & =\frac{\sqrt{2}\centerdot \sqrt{5}+\sqrt{2}\centerdot 2+3\centerdot \sqrt{5}+3\centerdot 2}{5-4}=\sqrt{2\centerdot 5}+2\sqrt{2}+3\sqrt{5}+6 \\ | ||
+ | & =6+2\sqrt{2}+3\sqrt{5}+10 \\ | ||
+ | \end{align}</math> |
Version vom 08:50, 23. Sep. 2008
We use the standard method and augment the fraction with the conjugate of the denominator \displaystyle \sqrt{5}+2. Then the conjugate rule gives
\displaystyle \begin{align}
& \frac{\sqrt{2}+3}{\sqrt{5}-2}=\frac{\sqrt{2}+3}{\sqrt{5}-2}\centerdot \frac{\sqrt{5}+2}{\sqrt{5}+2}=\frac{\left( \sqrt{2}+3 \right)\left( \sqrt{5}+2 \right)}{\left( \sqrt{5} \right)^{2}-2^{2}} \\
& =\frac{\sqrt{2}\centerdot \sqrt{5}+\sqrt{2}\centerdot 2+3\centerdot \sqrt{5}+3\centerdot 2}{5-4}=\sqrt{2\centerdot 5}+2\sqrt{2}+3\sqrt{5}+6 \\
& =6+2\sqrt{2}+3\sqrt{5}+10 \\
\end{align}