Given a polynomial f(x), if (x − 4) is a factor, what else must be true?

f(0) = 4
f(0) = −4
f(4) = 0
f(−4) = 0
thank you in advance

Respuesta :

hartnn
if x-a is the factor of f(x) then
f(a) = 0

Hence,
if x-4 is a factor of f(x) then f(4) = 0

option C

Answer:

[tex]f(4)=0[/tex]


Step-by-step explanation:

The Remainder Theorem states that when you divide a polynomial [tex]f(x)[/tex]  by a linear factor  [tex](x-a)[/tex] , where [tex]a[/tex]  is a constant, the remainder is [tex]f(x)[/tex]  evaluated at [tex]x=a[/tex]

Moreover, according to the Factor Theorem, an extension of the Remainder Theorem, if the remainder of the function [tex]f(x)[/tex] is 0 when evaluated at [tex]x=a[/tex] , then [tex](x-a)[/tex]  is said to be a factor of the polynomial [tex]f(x)[/tex]

Given the 2 theorems above, it follows that if [tex](x-4)[/tex]  is a factor of [tex]f(x)[/tex] , then the remainder is equal to 0 when [tex]f(x)[/tex] is evaluated at [tex]x=4[/tex]

Which means [tex]f(4)=0[/tex]

Third answer choice is correct.


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