Hello,

in the section "quadratic and cubic equations", the part on the
cubic, there is written: "Equations ... are arranged both to minimize
roundoff error, and also (as pointed out bu A. J. Glassman)
to ensure that no choice of branch for the complex cube root can
result in the spurious loss of a distinct root.

I have some questions:

1) why do these formula's minimize roundoff error?

2) Where did A. J. Glassman explained this statement?
Could I obtain the refence to a book or paper?

Best regards,

FLconcorde