(12C Platinum) Internal Precision Test

[Dieter]

(01-01-2019 03:44 AM)Gamo Wrote:  The Internal Precision as shown in brochure stated
is 15 digits.
The reason that 12C Platinum took more iterations because of the 15 digits internal precision which mean that this takes more iterations than the standard 12C and what shown on display is 10 digits.

Let's look at this a bit more closely.

The reason for the different number of iterations is not the 15-digit vs. 13-digit internal precision of both calculators. The program calculates with 12 and 10 digit precision, and this is what causes the difference.

The e approximation changes as long as 1/n! stays ≥ 5E–12 or 5E–10, respectively. This happens up to n=14 and n=12, respectively. This is what causes the different number of iterations. The fact that you determined 14 and 11 (instead of 12) is cause by random roundoff errors.

Dieter