CASA Function: realroot_a

Isolate real roots of a polynomial with algebraic number coefficients in strictly seperated intervals using de-recursive algorithms and norm.

Calling Sequence:

Parameters:

minimal : polynom
interval : list
poly : polynom
widthgoal : numeric

Result:

R : list

Description:

Examples:

> eq1 := expand(2*x^4 - 3*x^2*y + y^2*(y-1)^2);

[Maple Math]

> Ay := 8*y^2 - 16*y - 1:

> a := RootOf(Ay):

> eq2 := subs(y=a, eq1):

> # Algebraic sqrfree

> Geq2 := evala(Gcd(eq2, diff(eq2, x))):

> evala(Divide(eq2, Geq2, evaln(eq2))):

> eq2 := primpart(subs(a=y, eq2));

[Maple Math]

> realroot_a(Ay, [-10,10], eq2);

[Maple Math]

See Also:

[CASA] [realroot_sb] [[realroot]]