Calculation of determinant on HP-15C

[Werner]

The 15C, as well as the 42S, have one peculiarity not mentioned before: they will alter a degenerate factorisation (ie. DET=0) by a small amount (1e-12 in the case of the 42S).
Take the obvious case

[[ 1 1 0 ]
[ 1 1 0 ]
[ 0 0 1 ]]

and compute its determinant.. the 42S returns -2e-12.
This is obviously not a consequence of roundoff here.
See the 15C Advanced Functions Handbook pg 117-118 for an explanation.

Cheers, Werner