Skip to content

Instantly share code, notes, and snippets.

@soraphis
Created February 16, 2014 13:42
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save soraphis/9034405 to your computer and use it in GitHub Desktop.
Save soraphis/9034405 to your computer and use it in GitHub Desktop.
logarithmusregel
# Beweis Logarithmusregel
## Logarithmisch Differenzieren
**zz:** $ log_a(x) = \frac 1{x * ln(a)} $
### teil 1:
##### sonderfall $ a = e $ → $ log_a = ln $
**zz:** $ ln(x) = \frac1x$
$$ e^{ln(x)} = x \ \ | \frac d{dx}$$
$$ \frac d{dx}e^{ln(x)} = \frac {dx}{dx}$$
$$ e^{ln(x)} \frac {d \ ln(x)}{dx} = 1 \ \ | : e^{ln(x)}$$
$$ \frac {d \ ln(x)}{dx} = \frac1{e^{ln(x)}}$$
### teil 2:
##### erweiterung auf beliebige basis a
$$ log_a(x) = \frac{ln(x)}{ln(a)} \ \ | \frac d{dx}$$
$$ \frac {d\ log_a(x)}{dx} = \frac{ln(x)}{ln(a)}$$
$$ \frac {d\ log_a(x)}{dx} = \frac{1}{x\ ln(a)}$$
$q.e.d$
> Written with [StackEdit](https://stackedit.io/).
# Beweis Logarithmusregel
## Logarithmisch Differenzieren
**zz:** $ log_a(x) = \frac 1{x * ln(a)} $
### teil 1:
##### sonderfall $ a = e $ → $ log_a = ln $
**zz:** $ ln(x) = \frac1x$
$$ e^{ln(x)} = x \ \ | \frac d{dx}$$
$$ \frac d{dx}e^{ln(x)} = \frac {dx}{dx}$$
$$ e^{ln(x)} \frac {d \ ln(x)}{dx} = 1 \ \ | : e^{ln(x)}$$
$$ \frac {d \ ln(x)}{dx} = \frac1{e^{ln(x)}}$$
### teil 2:
##### erweiterung auf beliebige basis a
$$ log_a(x) = \frac{ln(x)}{ln(a)} \ \ | \frac d{dx}$$
$$ \frac {d\ log_a(x)}{dx} = \frac{ln(x)}{ln(a)}$$
$$ \frac {d\ log_a(x)}{dx} = \frac{1}{x\ ln(a)}$$
$q.e.d$
> Written with [StackEdit](https://stackedit.io/).
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment