# Logarithms

• Feb 7th 2008, 12:44 PM
Mortifix
Logarithms
We just started logarithms today and I was wondering if there was a program that had a log solver or the rules. I was using a math program, but the log formulas were different from the ones I just learned in class today.

I don't know how I would write out the formulas to explain...sorry.
• Apr 5th 2008, 07:47 AM
mx-
Which TI are you using?

If you are using a Computer algebra system (CAS) calculator such as the TI 89 or 89T.

You can just use the solve function... solve(

Log rules may seem hard to remember at first, but after sometime and practice you know them off by heart.
• Apr 6th 2008, 01:44 PM
meg2001
Theres some good programs on the ticalc site for logs but u need a cord to download them to your calculator
• Apr 7th 2008, 09:21 AM
Mathstud28
I am guessing
that you have something like this in clacc $\log_7(x)$ and all you have on your calculator is either $\ln(x)$ or $log(x)=log_{10}(x)$...to get $log_a(x)$ into these forms use the change of base formula...so $log_a(x)=\frac{\ln(x)}{\ln(a)}$...so if you were trying to solve say $log_7(x)+\ln(x)-5=0$ using rules you know and the one I just said you could rewrite it as $\frac{\ln(x)}{\ln(7)}+\ln(x)-5=0$ then you might be in a form to imput it inot your calculator...hope this helps