(11C) CUBIC EQUATION

[Valentin Albillo]

(06-09-2018 07:50 PM)Dieter Wrote:  

(06-09-2018 11:49 AM)Gamo Wrote:  B Display 3 R/S 0.25 // D is greater than or equal zero go ahead with R/S

The returned 3 is the first root. But what is "0,25"?

Most probably some sort of discriminant, either of the original cubic, some reduced cubic (if that's how he's computing the root, I didn't read the code) or of the quadratic after deflation. If it is >=0 the remaining two roots are real, else they are complex.

I'd bet it's the discriminant of the deflated quadratic, i.e., the equivalent of b^2-4*a*c in the classical formula for the roots of a quadratic equation (not the a,b,c he uses in his instructions).

V.
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