Which of the following are roots of the polynomial function below?
Check all that apply.
F(x) = 2x3 - 5x2 + 2x + 1
A. 1
3-17
B.
4
C.
3+√17
4
D.
5-/10
6
S+√10
E.
6

Respuesta :

Answer:

[tex]f(x) = 2x^3 -5x^2+2x+1\\\\by \ trail \ and \ error, \\\\f(1) = 2(1^3) -5(1^2) +2(1) +1 = 2 - 5 + 2 + 1 = 0\\\\Therefore, 1 \ is \ a \ root \ of \ f(x).\\\\=> (x -1) \ is \ a \ factor \ of \ f(x).[/tex]

Now using long division,

[tex]\mathrm{Factor}\:2x^3-5x^2+2x+1:\quad \left(x-1\right)\left(2x^2-3x-1\right)[/tex]

[tex]\quad \left(x-1\right)\left(2x^2-3x-1\right)\\\\(x-1)(x-\frac{3+\sqrt{17} }{4})(x+\frac{3-\sqrt{17} }{4} )[/tex]

Therefore , the roots are

                         [tex]1 , \frac{3+\sqrt{17} }{4} , \frac{3-\sqrt{17} }{4}[/tex]