# Need Help With a Logarithmic Problem

• Jan 2nd 2013, 08:06 PM
jorgon1022
Need Help With a Logarithmic Problem
I dont understand what I am doing wrong.

Here it is
Given log a ^2= .69, log a ^3=1.10 and log a ^5=1.61, use the properties of logarithms to evaluate:

log a 1/square root of 15

Can any of you please help with this problem? I would really appreciate it.
• Jan 2nd 2013, 08:11 PM
ibdutt
Re: Need Help With a Logarithmic Problem
The question is not clear. What do you want to find
log a 1/square root of 15???? or log a^1/square root of 15??
• Jan 2nd 2013, 08:19 PM
jorgon1022
Re: Need Help With a Logarithmic Problem
Attachment 26452

Here is a picture of the problem. Thank you.
• Jan 3rd 2013, 06:02 AM
skeeter
Re: Need Help With a Logarithmic Problem
$\log_a{\frac{1}{\sqrt{15}}} = -\log_a{\sqrt{15}} = -\frac{1}{2}\log_a{15} = -\frac{1}{2}\log_a(3 \cdot 5) = -\frac{1}{2}\left(\log_a{3}+\log_a{5}\right)$