next up previous contents index
suivant: Exact values of rational monter: Exact roots of a précédent: Exact bounds for complex   Table des matières   Index


Exact bounds for real roots of a polynomial : realroot

realroot has 2 or 4 arguments : a polynomial and a real number $ \epsilon$ and optionnally two reals numbers $ \alpha$,$ \beta$.
realroot returns a list of vectors. To find the real roots of x3 + 1, input:
realroot(x^3+1, 0.1)
Output :
[[-1,1]]
To find the real roots of x3 - x2 - 2x + 2, input:
realroot(x^3-x^2-2*x+2, 0.1)
Output :
[[1,1],[[(-3)/2,(-45)/32],1],[[45/32,3/2],1]]
To find the real roots of x3 - x2 - 2x + 2 in the interval [0;2], input:
realroot(x^3-x^2-2*x+2, 0.1,0,2)
Output :
[[1,1],[[11/8,23/16],1]]


next up previous contents index
suivant: Exact values of rational monter: Exact roots of a précédent: Exact bounds for complex   Table des matières   Index
giac documentation written by Renée De Graeve and Bernard Parisse