Preserved Topic: help with a little math =) (Page 1 of 1)

i was just curious on how one solves this

((x-1)/x)^x >= 9/25

it's something i cooked up from a general sucession (1+1/n)^n related problem
i would say the solution lies in the combined use of logaritmization and raditiacion, but from there went in circles

the result should be presented in the form [x,+00[

anyone?

~this is not a signature~

but i am more interested in the method, of course, so it's no use mathcheating. Done that, been there. I got the result but not the method

[This message has been edited by Arthemis (edited 07-15-2002).]

Maple returns something with LambertW(x) in it, which it defines as "the function which satisfies LambertW(x) * exp(LambertW(x)) = x". So this is at *least* one semester ahead of me. I've never really dealt with such functions before.

maple?

this -> http://www.mappleapps.com | | http://www.indiana.edu/~statmath/math/maple/gettingstarted/1.html#1a ?


you recommend it?

[This message has been edited by Arthemis (edited 07-16-2002).]

I wouldn't recommend it. I have it because my school gives it to everyone who buys the laptops they provide. It does the trick, and is powerful, but the commands that you have to type are completely unintuitive. It's just... poorly made. For instance, having to use separate commands for everything that can be done in 2D for its 3D equivalent is ridiculous. And the notations it uses aren't standard. Assignments aren't easily made. Functions aren't easy to use. Overall, it sucks. Get a TI-89 or 92. I loved my '89 until I lost it (I suspect it was stolen).

Yeah, I loved my Ti-92. I was so bored in physics class that I wrote a hangman program for it. It only had a six word dictionary, but the error checking and the syntax routines weren't too shabby.

Arthemis: Sorry, chum, haven't done Lambert equations for months, and my books are in a box somewhere.

mhm.....slime seems to be the math-man here....good to know....

Well, I've never seen lambert equations. What sort of class would you learn about them in?

ya, i remember Lamnbert's W function. It's pretty vague, letting some variable equal a part of the function, then solving the equation in relation to that variable. I'm not an expert in it, but ya, it should help ya out with that problem.

any idea on how to acutally do it though?

Koan 63, written on the wall of cell number 250:
Those who Believe
Can
Those who Try
Do
Those who Love
Live

That LambertW function sounds real familiar but it'd been awhile since I've used it, so afriad I'm not a lot of help myself here...

However, might want to check this link out

Archieved Sparknotes Forum entry


________________________________________________________________
-- Jack of all trades, master of that which has my attention at
the moment.

I think it was either Advanced Calc or Multidimensional/Multivariable Calc. Second or third year stuff.

Sounds like my professor skipped it then =) Or maybe I didn't quite get there yet.

Yea, I just finished Calc3, Multivariable Calculus, last Spring, which used it some, but not enough to really burn it into my memory. I don't remember it being really emphasized though... Just a kind of side-note in another section.


________________________________________________________________
-- Jack of all trades, master of that which has my attention at
the moment.