trying to create a LOG() function

[Craig D.S.]

Greetings

I am running into some difficulty trying to create a LOG() function for plotting out some of the derived Inverse hyperbolic functions

getting the error ' Cannot take sqrt or log of a negative number'

Some guidence through this matter would be much appreciated

Thanks

[klinzey]

Craig,

The problem is with the evaluation of:

atanh:= (Ln((1 + v) / (1 - v)))/ln(10) / 2;

(1 + v) / (1 - v) evaluates to negative number. (-0.517... for the first iteration and it stays negative for several more.)

Kevin

[Craig D.S.]

Is there a work around to plot this function? and other derived trig functions w/ the Log() in it?

I was able to do it in TurboCAD VBA...