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

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



Answer :

To determine the nature of the function \( f(x) = (x^m + 9)^2 \), let's analyze whether it is even, odd, or neither for different values of \( m \).

### Definitions:

1. Even Function: A function \( f(x) \) is even if \( f(x) = f(-x) \) for all \( x \) in its domain.
2. Odd Function: A function \( f(x) \) is odd if \( f(x) = -f(-x) \) for all \( x \) in its domain.

### Analysis:

First, we substitute \( -x \) into the function \( f(x) \) to see how \( f(-x) \) looks:

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

Next, we consider two cases based on whether \( m \) is even or odd.

#### Case 1: \( m \) is even

If \( m \) is even, then \( (-x)^m = x^m \). Substituting this into \( f(-x) \), we get:

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

Comparing this with the original function \( f(x) \):

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

We can see that:

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

Thus, if \( m \) is even, \( f(x) \) is an even function.

#### Case 2: \( m \) is odd

If \( m \) is odd, then \( (-x)^m = -x^m \). Substituting this into \( f(-x) \), we get:

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

To compare this with the original function \( f(x) \), let's expand both expressions:

For \( f(x) \):

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

And for \( f(-x) \):

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

Squaring removes the sign difference, hence \( f(-x) \neq -f(x) \) and it does not satisfy \( f(-x) = f(x) \) either. Therefore, \( f(x) \) can neither be odd nor even in this case.

### Conclusion:

- \( f(x) \) is an even function for all even values of \( m \).
- \( f(x) \) is neither even nor odd for odd values of \( m \).

The correct statement about \( f(x) \) is:

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

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