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## Exact values of rational roots of a polynomial : rationalroot

rationalroot takes 1 or 3 arguments : a polynomial and optionnally two reals numbers ,.
• If rationalroot has 1 argument, rationalroot returns the list of the value of the rational roots of the polynomial without multiplicity.
• If rationalroot has 3 arguments, rationalroot returns only the rational roots of the polynomial which are in the interval [,].
To find the rational roots of 2*x3 -3*x2 - 8*x + 12, input:
rationalroot(2*x^3-3*x^2-8*x+12)
Output :
[2,3/2,-2]
To find the rational roots of 2*x3 -3*x2 - 8*x + 12 in [1;2], input:
rationalroot(2*x^3-3*x^2-8*x+12,1,2)
Output :
[2,3/2]
To find the rational roots of 2*x3 -3*x2 + 8*x - 12, input:
rationalroot(2*x^3-3*x^2+8*x-12)
Output :
[3/2]
To find the rational roots of 2*x3 -3*x2 + 8*x - 12, input:
rationalroot(2*x^3-3*x^2+8*x-12)
Output :
[3/2]
To find the rational roots of (3*x - 2)2*(2x + 1) = 18*x3 -15*x2 - 4*x + 4, input:
rationalroot(18*x^3-15*x^2-4*x+4)
Output :
[(-1)/2,2/3]

suivant: Exact values of the monter: Exact roots of a précédent: Exact bounds for real   Table des matières   Index
giac documentation written by Renée De Graeve and Bernard Parisse