Select the correct answer.

If [tex]$f(x)=\sqrt{x}-x$[/tex] and [tex]$g(x)=2x^3-\sqrt{x}-x$[/tex], find [tex][tex]$f(x)-g(x)$[/tex][/tex].

A. [tex]$-2x^3 + 2\sqrt{x}$[/tex]

B. [tex]$-2x^3 - 2x - 2\sqrt{x}$[/tex]

C. [tex][tex]$-2x^3 - 2x$[/tex][/tex]

D. [tex]$2x^3 - 2x + 2\sqrt{x}$[/tex]



Answer :

To find [tex]\( f(x) - g(x) \)[/tex] given the functions [tex]\( f(x) = \sqrt{x} - x \)[/tex] and [tex]\( g(x) = 2x^3 - \sqrt{x} - x \)[/tex], follow these steps:

1. First, write down the expressions for [tex]\( f(x) \)[/tex] and [tex]\( g(x) \)[/tex]:
[tex]\[ f(x) = \sqrt{x} - x \][/tex]
[tex]\[ g(x) = 2x^3 - \sqrt{x} - x \][/tex]

2. Now, compute [tex]\( f(x) - g(x) \)[/tex]:
[tex]\[ f(x) - g(x) = (\sqrt{x} - x) - (2x^3 - \sqrt{x} - x) \][/tex]

3. Distribute the negative sign in front of [tex]\( g(x) \)[/tex]:
[tex]\[ f(x) - g(x) = \sqrt{x} - x - 2x^3 + \sqrt{x} + x \][/tex]

4. Combine like terms:
[tex]\[ f(x) - g(x) = (\sqrt{x} + \sqrt{x}) + (-x + x) - 2x^3 \][/tex]
[tex]\[ f(x) - g(x) = 2\sqrt{x} - 2x^3 \][/tex]

Thus, the simplified form of [tex]\( f(x) - g(x) \)[/tex] is:
[tex]\[ f(x) - g(x) = 2\sqrt{x} - 2x^3 \][/tex]

So the correct answer is:
A. [tex]\( -2x^3 + 2\sqrt{x} \)[/tex]