factoriser f(x)=(x*x*x)-11x+14
f(2) = 8-22+14 = 0 donc f(x) est divisible par x-2. appliquons Hörner
1 0 -11 14
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2 2 4 -14
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1 2 -7 0
x³ -11x +14 = (x-2)(x² +2x -7) = (x-2)(x + 1 + 2rac(2))(x+1-2rac(2))