Question

question #9 determine which of the following numbers is not a root of f(x)=x^3 - 9x^2 + 26x - 24. 1 3 4 2

Explanation:

Step1: Substitute x = 1

$f(1)=1^{3}-9\times1^{2}+26\times1 - 24=1 - 9+26 - 24=-6$

Step2: Substitute x = 3

$f(3)=3^{3}-9\times3^{2}+26\times3 - 24=27-81 + 78-24=0$

Step3: Substitute x = 4

$f(4)=4^{3}-9\times4^{2}+26\times4 - 24=64-144 + 104-24=0$

Step4: Substitute x = 2

$f(2)=2^{3}-9\times2^{2}+26\times2 - 24=8-36 + 52-24=0$

Answer:

1