Given:
[tex]\[ f(x) = x^3 - 5x + 1, \quad -8 \leq x \ \textless \ 5 \][/tex]
[tex]\[ g(x) = 4x^3 - 10x, \quad 2 \ \textless \ x \leq 12 \][/tex]

Calculate [tex]\((g-f)(x)\)[/tex].

A. [tex]\((g-f)(x) = 3x^3 + 5x - 1\)[/tex]
B. [tex]\((g-f)(x) = 3x^3 - 5x - 1\)[/tex]
C. [tex]\((g-f)(x) = x^3 - 5x\)[/tex]
D. [tex]\((g-f)(x) = x^3 - 15x - 1\)[/tex]



Answer :

To find [tex]\((g - f)(x)\)[/tex], we need to subtract [tex]\(f(x)\)[/tex] from [tex]\(g(x)\)[/tex].

The functions given are:

[tex]\( f(x) = x^3 - 5x + 1 \)[/tex] defined on the interval [tex]\([-8, 5)\)[/tex]
[tex]\( g(x) = 4x^3 - 10x \)[/tex] defined on the interval [tex]\((2, 12]\)[/tex]

First, we write the expressions for [tex]\(g(x)\)[/tex] and [tex]\(f(x)\)[/tex]:

[tex]\(f(x) = x^3 - 5x + 1\)[/tex]
[tex]\(g(x) = 4x^3 - 10x\)[/tex]

To find [tex]\((g - f)(x)\)[/tex], we subtract [tex]\(f(x)\)[/tex] from [tex]\(g(x)\)[/tex]:

[tex]\[ (g - f)(x) = g(x) - f(x) \][/tex]

Substitute the given functions [tex]\(g(x)\)[/tex] and [tex]\(f(x)\)[/tex]:

[tex]\[ (g - f)(x) = (4x^3 - 10x) - (x^3 - 5x + 1) \][/tex]

Distribute the negative sign across the terms in [tex]\(f(x)\)[/tex]:

[tex]\[ (g - f)(x) = 4x^3 - 10x - x^3 + 5x - 1 \][/tex]

Combine like terms:

[tex]\[ (g - f)(x) = (4x^3 - x^3) + (-10x + 5x) - 1 \][/tex]

Simplify the expressions:

[tex]\[ (g - f)(x) = 3x^3 - 5x - 1 \][/tex]

Thus, the correct expression for [tex]\((g - f)(x)\)[/tex] is:

[tex]\[ (g - f)(x) = 3x^3 - 5x - 1 \][/tex]

The correct option among the given choices is:

[tex]\[ (g - f)(x) = 3x^3 - 5x - 1 \][/tex]