Lösung 3.3:5b
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
K (Lösning 3.3:5b moved to Solution 3.3:5b: Robot: moved page) |
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- | {{ | + | By using the logarithm laws, |
- | < | + | |
- | {{ | + | |
+ | <math>\lg a+\lg b=\lg \left( a\centerdot b \right)</math> | ||
+ | |||
+ | |||
+ | <math>\text{log }a-\text{ log }b=\text{log}\left( \frac{a}{b} \right)</math> | ||
+ | |||
+ | we can collect together the terms into one logarithmic expression | ||
+ | |||
+ | |||
+ | <math>\begin{align} | ||
+ | & \ln 8-\ln 4-\ln 2=\ln 8-\left( \ln 4+\ln 2 \right)=\ln 8-\ln \left( 4\centerdot 2 \right) \\ | ||
+ | & =\ln \frac{8}{4\centerdot 2}=\ln 1=0, \\ | ||
+ | \end{align}</math> | ||
+ | |||
+ | |||
+ | where ln 1 =0, since | ||
+ | <math>e^{0}=1</math> | ||
+ | (the equality | ||
+ | <math>a^{0}=1</math> | ||
+ | holds for all | ||
+ | <math>a\ne 0</math> | ||
+ | ). |
Version vom 08:26, 26. Sep. 2008
By using the logarithm laws,
\displaystyle \lg a+\lg b=\lg \left( a\centerdot b \right)
\displaystyle \text{log }a-\text{ log }b=\text{log}\left( \frac{a}{b} \right)
we can collect together the terms into one logarithmic expression
\displaystyle \begin{align}
& \ln 8-\ln 4-\ln 2=\ln 8-\left( \ln 4+\ln 2 \right)=\ln 8-\ln \left( 4\centerdot 2 \right) \\
& =\ln \frac{8}{4\centerdot 2}=\ln 1=0, \\
\end{align}
where ln 1 =0, since
\displaystyle e^{0}=1
(the equality
\displaystyle a^{0}=1
holds for all
\displaystyle a\ne 0
).