TI-89 Titanium Help: Solve Logarithmic Problems Easily

[RaNe]

Hi,

I'm working out some problems on my TI-89 Titanium, and I've run into a roadblock.

How do I put a base for a log?

Thanks a lot.

 

[Xezlec]

ln(thing you want the log of) / ln(base of the log)

As far as I know, that's the only way to do it on a TI. but it's not hard.

 

[z-component]

That's the way I do it; just the standard log change of base formula. So ln(2) is just the log of 2, and ln(2)/ln(10) is log of 2, base 10. You can also see that ln(2)/ln(e), the base e log which is the natural log, will be just ln(2) since ln(e) evaluates to 1.

 

[Hymne]

I borrow this thread a little if its okey..
I got a problem with mine TI-89.
Whay I want to calculate a root i press "diamond + 9 + x + , + y + enter" which should give me x^1/y. But all i get is what i just pressed, i.e. the answer i get is root(x,y).
Please help me.

 

[z-component]

To find a root of x, use the zeros() function. Type zeros(expression,variable), or, alternatively, solve(equation,variable), when the equation is the same expression but set to zero, and the variable is x.

zeros(4x^2+3x+5,x) or solve(4x^2+3x+5=0,x) returns the roots.

 

[Hymne]

Okey, but do you know where the problem for the root function could lie?
Could it be any setting?

EDIT: The problem was that I had changed languege... It now works again.

 

[kevinf]

another way to do log is to log(number, base)

 

[Xezlec]

another way to do log is to log(number, base)

That doesn't work for me.

 

[Mk]

I think he has one of those Apps like Omnicalc to upgrade the features kind of. That's also one way you can do it, just with a comma. Change of base requires a little more typing.

 

[morgans]

if you press the yellow Diamond button and then press 7 then log will show up. much less typing for all you lazy people like me

 

[z01d]

another way to do log is to log(number, base)

i.e. solve(log(x,8)=2/3,x)

x=4