HP Prime: Rounding error in determinant

[Stephan Matthys]

Let's assume the following matrix:

[[4 5 7] [8 9 0] [5 6 2]]

The determinant (as given by my Prime (hardware & emulator, both running version 2013 8 13. Rev:5016)) is 13.

The transposed matrix is:

[[4 8 5] [5 9 6] [7 0 2]]

The corresponding determinant is 13.0000000002

Why? Shouldn't they be the same?

btw: my HP15C also makes a small error (-2e-8) in the determinant of the transposed matrix...

[Eddie W. Shore]

Short Answer: Floating Point Computations (I think)

[Gilles Carpentier]

Hi

In CAS mode you will get the same and exact result.

Probably some rounding effect in HOME

By the way the HP50 give 13 both in exact and approx mode

Edited: 25 Oct 2013, 7:16 p.m.

[Walter B]

FWIW, the WP 34S returns exact 13 for both the original and its transposed.

d:-)