HP calcs are really not that accurate..

[Craig Bladow]

(12-01-2017 07:49 PM)DA74254 Wrote:  I put 2 on the stack and sqrt it 5 times, then squared it back. All my 5 HP's returned 1.99999999979 instead of 2.0. That goes for the Android Pro version as well.

I ran this in NQ41, which uses double precision floating point numbers, subtracting 2 and got the following result.

Code:


Welcome to NQ41 (Not Quite a -41!)
Version 0.003
Copyright © 2017 Craig Bladow. All rights reserved.
This experimental software is released for the sole purpose of testing and feedback and without warranty of any kind.

Input commands and numbers, separated by spaces, and press return.
A space or return after a number is the same as the command 'enter'.
Use 'exit' to quit and 'catalog 3' for a list of commands.

> 2 sqrt sqrt sqrt sqrt sqrt x^2 x^2 x^2 x^2 x^2 2 -
x: -3.5527e-15 y:0.0000 z:0.0000 t:0.0000 l:2.0000

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