Find x-intercept in log

• September 28th 2009, 04:06 PM
BeSweeet
Find x-intercept in log
I need to find the x-intercept of http://img35.imageshack.us/img35/885...90928at604.jpg. It's (?, 0). Can't seem to find it :(. According to the graph:
http://img16.imageshack.us/img16/139...b4329b6d30.gif
The line doesn't cross the x-axis anywhere.
• September 28th 2009, 04:10 PM
pickslides
make y = 0 and solve for x.

Use $a^b= c \Rightarrow b = \log_ac$
• September 28th 2009, 04:16 PM
BeSweeet
Quote:

Originally Posted by pickslides
make y = 0 and solve for x.

Use $a^b= c \Rightarrow b = \log_ac$

Did all that. Somehow got -2, which is incorrect (Thinking)...
• September 28th 2009, 04:31 PM
pickslides
$0 = \log_5(x-1)+4$

$-4 = \log_5(x-1)$

$5^{-4} = x-1$

$5^{-4} +1= x$

$\frac{1}{5^{4}} +1= x$

Can you finish it?
• September 28th 2009, 05:25 PM
BeSweeet
Yes :). Thanks! Got it. I should have known...