Hello,

sage: A = matrix([[1, 0.106, 1.212], [3.8759765625, 0.04801171875,
....: 3.972], [3.0625, 0.09325, 3.249]])
sage: A.rank()
3
sage: A.det()
0.000000000000000

Though sage computes the rank to be 3, the determinant is negligible.
Mathematica says the rank of this matrix is 2, and that its
determinant is -4.02835*10^(-17) (and reduces the system to `z =
-1.04202x + 0.0210102y`). Perhaps it's just an issue of the standard
precision for floating point real numbers. The matrix in question is
certainly very "ill-conditioned".

By the way, this system doesn't have an infinite number of unique
solutions, though it does have an infinite number of distinct
solutions (just a quibble...).

-Keshav

On Jan 19, 6:58 am, Ben Edwards <[email protected]> wrote:
> > Thus (0,0,0) is the unique solution of your system.
>
> Uh... not quite 'Thus'. The system in fact has an infinite number of
> unique solutions, as the original poster pointed out. Though I don't
> know why sage converges on [0,0,0]. Also just because a second sage
> method gives the same result as the first does not mean something
> isn't amiss.

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