6.29.4 Exact bounds for positive real roots of a polynomial: VAS_positive
The VAS_positive command uses the
Vincent-Akritas-Strzebonski algorithm to find intervals containing the
positive real roots of polynomials.
-
VAS_positive takes one argument:
P, a polynomial.
- VAS_positive(P) returns a list of
intervals which contain the positive real roots of P, where each
interval contains exactly one root.
Examples.
-
Input:
VAS_positive(x^3 - 7*x + 7)
Output:
⎡
⎢
⎢
⎢
⎢
⎢
⎢
⎢
⎣ | | ⎤
⎥
⎥
⎥
⎥
⎥
⎥
⎥
⎦ |
- Input:
VAS_positive(x^5 + 2*x^4 - 6*x^3 - 7*x^2 + 7*x + 7)
Output:
⎡
⎢
⎢
⎢
⎢
⎢
⎢
⎢
⎣ | | ⎤
⎥
⎥
⎥
⎥
⎥
⎥
⎥
⎦ |
- Input:
VAS_positive(x^3 - x^2 -2*x + 2)
Output: