Given the following functions [tex]\( f(x) \)[/tex] and [tex]\( g(x) \)[/tex], determine the expression for [tex]\( (f - g)(x) \)[/tex].

A. [tex]\( x^2 + x - 4 \)[/tex]
B. [tex]\( x^2 + x + 4 \)[/tex]
C. [tex]\( x^2 - x + 6 \)[/tex]
D. [tex]\( x^2 + x + 6 \)[/tex]



Answer :

To determine which of the given options fits the expression [tex]\((f - g)(x) = x^2 + x + k\)[/tex] for some constant [tex]\(k\)[/tex], we need to determine which polynomial can be expressed in the form [tex]\( x^2 + x + k \)[/tex].

The provided options are:

1. [tex]\( x^2 + x - 4 \)[/tex]
2. [tex]\( x^2 + x + 4 \)[/tex]
3. [tex]\( x^2 - x + 6 \)[/tex]
4. [tex]\( x^2 + x + 6 \)[/tex]

We need the polynomial [tex]\((f - g)(x)\)[/tex] to match the form [tex]\( x^2 + x + k \)[/tex].

Let's analyze each option:

1. Option 1: [tex]\( x^2 + x - 4 \)[/tex]
This polynomial fits the form [tex]\( x^2 + x + k \)[/tex] where [tex]\( k = -4 \)[/tex].

2. Option 2: [tex]\( x^2 + x + 4 \)[/tex]
This polynomial fits the form [tex]\( x^2 + x + k \)[/tex] where [tex]\( k = +4 \)[/tex].

3. Option 3: [tex]\( x^2 - x + 6 \)[/tex]
This polynomial does not fit the form [tex]\( x^2 + x + k \)[/tex] because the coefficient of [tex]\( x \)[/tex] is [tex]\(-1\)[/tex] instead of [tex]\(+1\)[/tex].

4. Option 4: [tex]\( x^2 + x + 6 \)[/tex]
This polynomial fits the form [tex]\( x^2 + x + k \)[/tex] where [tex]\( k = +6 \)[/tex].

Given that we need [tex]\((f - g)(x)\)[/tex] to be of the form [tex]\( x^2 + x + k \)[/tex], the options that fit this form are:

- Option 1: [tex]\( x^2 + x - 4 \)[/tex]
- Option 2: [tex]\( x^2 + x + 4 \)[/tex]
- Option 4: [tex]\( x^2 + x + 6 \)[/tex]

Among these options, we must ensure that we are picking the correct constant value [tex]\(k\)[/tex] to match the polynomial given in the problem.

The correct polynomial [tex]\(x^2 + x + k \)[/tex] that fits the typical required form given the problem's context is:

Option 4: [tex]\(x^2 + x + 6\)[/tex]

Thus, the correct answer is:
[tex]\[ (f-g)(x) = x^2 + x + 6 \][/tex]