## A quotation by Tartaglia

[The poem in which he revealed the secret of solving the cubic to Cardan]

When the cube and the things together

Are equal to some discrete number,

^{1}

Find two other numbers differing in this one.

Then you will keep this as a habit

That their product shall always be equal

Exactly to the cube of a third of the things.

^{2}

The remainder then as a general rule

Of their cube roots subtracted

Will be equal to your principal thing.

^{3}

^{1}[Solve

*x*

^{3}+

*cx*=

*d*]

^{2}[Find

*u*,

*v*such that

*u*-

*v*=

*d*and

*uv*= (

*c*/3)

^{3}]

^{3}[Then

*x*=

^{3}√

*u*-

^{3}√

*v*]