If [tex]$f(x)=\left(x^m+9\right)^2$[/tex], which statement about [tex]$f(x)$[/tex] is true?

A. [tex][tex]$f(x)$[/tex][/tex] is an even function for all values of [tex]$m$[/tex].
B. [tex]$f(x)$[/tex] is an even function for all even values of [tex][tex]$m$[/tex][/tex].
C. [tex]$f(x)$[/tex] is an odd function for all values of [tex]$m$[/tex].
D. [tex][tex]$f(x)$[/tex][/tex] is an odd function for all odd values of [tex]$m$[/tex].



Answer :

To determine whether the function [tex]\( f(x) = (x^m + 9)^2 \)[/tex] is even or odd, we need to examine how [tex]\( f(x) \)[/tex] behaves when we replace [tex]\( x \)[/tex] with [tex]\(-x\)[/tex]:

[tex]\[ f(-x) = \left((-x)^m + 9\right)^2 \][/tex]

- For [tex]\( f(x) \)[/tex] to be an even function, [tex]\( f(-x) \)[/tex] must be equal to [tex]\( f(x) \)[/tex] for all [tex]\( x \)[/tex].
- For [tex]\( f(x) \)[/tex] to be an odd function, [tex]\( f(-x) \)[/tex] must be equal to [tex]\( -f(x) \)[/tex] for all [tex]\( x \)[/tex].

We will explore both cases.

### Case 1: Even function

To check if [tex]\( f(x) \)[/tex] is even, let's simplify [tex]\( f(-x) \)[/tex] and compare it to [tex]\( f(x) \)[/tex]:

[tex]\[ f(-x) = \left((-x)^m + 9\right)^2 \][/tex]

For [tex]\( f(x) \)[/tex] to be even, we need:

[tex]\[ \left((-x)^m + 9\right)^2 = \left(x^m + 9\right)^2 \][/tex]

This is only true if:

[tex]\[ (-x)^m + 9 = x^m + 9 \][/tex]

This further simplifies to:

[tex]\[ (-x)^m = x^m \][/tex]

This equation holds if and only if [tex]\( m \)[/tex] is even. Therefore, [tex]\( f(x) \)[/tex] is even when [tex]\( m \)[/tex] is even.

### Case 2: Odd function

To check if [tex]\( f(x) \)[/tex] is odd, we need to see if [tex]\( f(-x) = -f(x) \)[/tex]:

[tex]\[ f(-x) = \left((-x)^m + 9\right)^2 \][/tex]

For [tex]\( f(x) \)[/tex] to be odd, we need:

[tex]\[ \left((-x)^m + 9\right)^2 = -\left(x^m + 9\right)^2 \][/tex]

Since the square of any real number is always non-negative, [tex]\((-x)^m + 9\right)^2 and \left(x^m + 9\right)^2 are always non-negative. Hence, equating \( \left((-x)^m + 9\right)^2 \)[/tex] to the negative of [tex]\( \left(x^m + 9\right)^2 \ is only possible if both sides are zero, which is an impossibility unless \( x^m + 9 = 0 \)[/tex] for all [tex]\( x \)[/tex], which does not generally hold.

Therefore, the function [tex]\( f(x) = (x^m + 9)^2 \)[/tex] cannot be an odd function for any value of [tex]\( m \)[/tex].

Given these cases, we conclude that:

- [tex]\( f(x) \)[/tex] is an even function for all even values of [tex]\( m \)[/tex].

Hence, the correct statement about [tex]\( f(x) = (x^m + 9)^2 \)[/tex] is:

- [tex]\( f(x) \)[/tex] is an even function for all even values of [tex]\( m \)[/tex].