Need Aproximate expressions for : ln(x) and 1/ln(x) Thanks

[Boudy]

Hi there:
I am looking for approximate expressions for the two functions: ln(x) and 1/ln(x) . Any help?
Thanks in advance.

 

[mfb]

Approximations where, for what? Did you try Taylor expansions?

 

[mathman]

ln(x) is not analytic at x=0. You need to use a series around some other value. If you use the series for ln((1+x)/(1-x)) you will able to get a series for any y=(1+x)/(1-x) for -1<x<1.