Lösung 3.1:5b
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
K (Lösning 3.1:5b moved to Solution 3.1:5b: Robot: moved page) |
|||
Zeile 1: | Zeile 1: | ||
- | {{ | + | In order to eliminate |
- | < | + | <math>\sqrt[3]{7}=7^{{1}/{3}\;}</math> |
- | {{ | + | from the denominator, we can multiply the top and bottom of the fraction by |
+ | <math>7^{{2}/{3}\;}</math>. The denominator becomes | ||
+ | <math>7^{{1}/{3}\;}\centerdot 7^{{2}/{3}\;}=7^{{1}/{3+{2}/{3}\;}\;}=7^{1}=7</math> | ||
+ | and we get | ||
+ | |||
+ | |||
+ | <math>\frac{1}{\sqrt[3]{7}}=\frac{1}{7^{{1}/{3}\;}}=\frac{1}{7^{{1}/{3}\;}}\centerdot \frac{7^{{2}/{3}\;}}{7^{{2}/{3}\;}}=\frac{7^{{2}/{3}\;}}{7}.</math> |
Version vom 14:34, 22. Sep. 2008
In order to eliminate \displaystyle \sqrt[3]{7}=7^{{1}/{3}\;} from the denominator, we can multiply the top and bottom of the fraction by \displaystyle 7^{{2}/{3}\;}. The denominator becomes \displaystyle 7^{{1}/{3}\;}\centerdot 7^{{2}/{3}\;}=7^{{1}/{3+{2}/{3}\;}\;}=7^{1}=7 and we get
\displaystyle \frac{1}{\sqrt[3]{7}}=\frac{1}{7^{{1}/{3}\;}}=\frac{1}{7^{{1}/{3}\;}}\centerdot \frac{7^{{2}/{3}\;}}{7^{{2}/{3}\;}}=\frac{7^{{2}/{3}\;}}{7}.