I have a TI-84 plus calculator and when I try to perform a logarithmic function on it (say log(base 5) of 25, entered as log(5,25)) It will give me an error message saying Err:Argument. I have heard that there is some program that I can install on my calculator in order to allow it to perform logarithmic functions, does anyone here know anything about that, or could anyone direct me to the correct place to ask for such a thing? (I'm not entirely sure that this forum is the correct place for a question like this)

I'm not sure since I don't have that specific model, but is the a function called logBASE( in MATH? I noticed this on my TI 84 + SE so I thought this was when log( only did base ten in previous OSes. You can as just do log(number)/log(base to get your answer (I think). You might also wanna check if there is an update for your model

*The Silver Phantom welcomes you*

I also have a Ti 84 Plus, but it gives no error…

Wake me, when you need me.

Wait, that really gives no error? O_o It should :P

Check out the log() command and I will echo what Silver Phantom said. To perform logarithms of other bases, you can use the formula **log _{y}(x)=log(x)/log(y)** where the latter log can be in any base (so you can use

**ln(x)/ln(y)**, for example).

On the MP OSes (MP is "Math Print" and what is preloaded on new calcs), you can use the function logBASE(). Your log_{5}(25) would be written as **logBASE(25,5)**.

Z80 Assembly>English>TI-BASIC>Python>French>C>0

MasterChief is actually right, at least on my TI-84 Plus C Silver Edition and TI-84 Plus Silver Edition (2.55 MP).

log(3,5 is the same as logBASE(3,5 or log_{5}(3).

Edit (4/5/2014): On a TI-84 Plus Silver Edition (2.43 OS), log(3,5 throws an arguement error. I conclude that log([base],[number] does not work on non-MathPrint OS's.

You should document that on the log( page.

Timothy Foster - @tfAuroratide

Auroratide.com - Go here if you're nerdy like me

I am not sure if this is the same for non Math Print OSes. If someone could test and post here, that would be nice.

Also, I'm not sure if I can edit but I'll try.

So what is this MathPrint OS? I'm really new to all things technical with calculators but they seem interesting and I want to get further into it.

The Mathprint Os is a OS, that introduced besides of some other little features the Mathprint mode. With having the Mathprint mode turned on, all formulas appear like you also would write them.

For example:

√(iPart(A))

would appear like in Latex:

Or FnInt(f(x),x,a,b would be:

(2)However, being in Mathprint mode slows down all Basic programs that are executed in a very hard way.

Wake me, when you need me.

For a TI-84 Plus calculator, TI has a download for the 2.55MP OS.

It is here:

http://education.ti.com/en/us/software/details/en/400C88E8E75B4123BB7E90B6A676368D/ti84plusoperatingsystem