Hi

Being a holiday here, I had some extra time to play with this instrument.

Here is an issue with how the prime handles derivatives of functions that I do not comprehend. Maybe there is documentation in xcas about it, but ....

I define a function

b(x):=IFTE(x=0,1,x/(exp(x)-1)

This is a nice function that has a power series around 0 whose coefficients are the Bernoulli number B(n) divided by n!

So the derivative b'(0)=-1/2, but the HP prime computes b'(0)=+/- inf.

I cannot figure out how it does that. Thanks!

*Edited: 28 Nov 2013, 12:58 p.m. *