# logarithms and graphs??

• December 18th 2006, 12:41 PM
jillybean
logarithms and graphs??
how do I find the domain, x-intercept, and vertical asymptote of a log function?

example: f(x)= log x
7
• December 18th 2006, 01:40 PM
ThePerfectHacker
Quote:

Originally Posted by jillybean
how do I find the domain, x-intercept, and vertical asymptote of a log function?

example: f(x)= log x
7

I assume you mean,
$y=\log_7 x$

The domain are all positives.
Thus, $x>0$.

The vertical asymptote in a standard logarithm is the point where the domain breaks, i.e. $x=0$.

The x-intercept is to solve,
$\log_7 x=0$
Thus,
$7^0=x=1$