Programming Exercise (HP-15C, 15C LE - and others)

[Gerson W. Barbosa]

(03-29-2014 12:02 PM)Thomas Klemm Wrote:  

(03-29-2014 12:36 AM)Tugdual Wrote:  Nobody mentioned that entering $$\sum _{ K=1 }^{ 10000 }{ \frac { { (-1 })^{ K+1 } }{ K } }$$ on the Prime with no need for any sort of coding would instantly return 0.693097183025
Is that off scope consideration for this thread?
I know that the prime is blazing fast but the speed is so impressive that I wonder if the calculator is actually performing a loop?

That's the solution to:

Quote:(a) addition of terms from left to right

What about:

Quote:(b) addition of terms from right to left

You're right! I overlooked that when I suggested the Prime CAS was inexact for this one. It turns out I was inexact. Sorry!

The HP 50g gives the same result for item (a):

'∑(n=1,10000,(-1)^(n+1)/n)' EVAL --> 0.693097183025

For item (b), the Prime should give the same result we get on the HP 50g:

'∑(n=1,10000,(-1)^n/(10001-n))' EVAL --> 0.693097183059

However this takes too long on the HP 50g: 1 minute 50 seconds.

Cheers,

Gerson.