If [tex]$x=\left\{4^n-3n-1: n \in \mathbb{N}\right\}$[/tex] and [tex]$y=\{g(n-1): n \in \mathbb{N}\}$[/tex] where [tex]$\mathbb{N}$[/tex] is the set of natural numbers, then [tex]$x, y$[/tex] is equal to

A. [tex]$\mathbb{N}$[/tex]

B. [tex]$y-x$[/tex]

C. [tex]$x$[/tex]

D. [tex]$y$[/tex]



Answer :

To address the problem, let's break down and analyze the sets [tex]\( x \)[/tex] and [tex]\( y \)[/tex].

### Set [tex]\( x \)[/tex]
The set [tex]\( x \)[/tex] is defined as:
[tex]\[ x = \{4^n - 3n - 1 : n \in \mathbb{N}\} \][/tex]
This means that for every natural number [tex]\( n \)[/tex], we apply the function [tex]\( 4^n - 3n - 1 \)[/tex] to generate the elements of set [tex]\( x \)[/tex].

### Set [tex]\( y \)[/tex]
The set [tex]\( y \)[/tex] is defined as:
[tex]\[ y = \{g(n-1) : n \in \mathbb{N}\} \][/tex]
Here, [tex]\( g \)[/tex] is some function and [tex]\( y \)[/tex] consists of the outputs of [tex]\( g \)[/tex] when applied to [tex]\( n-1 \)[/tex] for each natural number [tex]\( n \)[/tex].

### Task
The problem is to determine the nature of the sets [tex]\( x \)[/tex] and [tex]\( y \)[/tex] without explicit information about the function [tex]\( g \)[/tex].

Given that essential information about [tex]\( g(n-1) \)[/tex] is missing, we can't explicitly determine the elements or nature of set [tex]\( y \)[/tex].

Since we are unable to fully determine the elements of [tex]\( y \)[/tex] due to insufficient information about the function [tex]\( g \)[/tex], and given the result we arrive at that is effectively [tex]\( None \)[/tex]:

- It indicates that despite the given definitions, a definitive comparison cannot be made regarding [tex]\( x \)[/tex] and [tex]\( y \)[/tex] due to the unspecified nature of [tex]\( g \)[/tex].

### Conclusion
Considering the lack of sufficient information to definitively characterize [tex]\( y \)[/tex] and compare it with [tex]\( x \)[/tex], the correct response, consistent with the output and reflection on the problem constraints given the undefined nature of [tex]\( g \)[/tex], would be:

```
None
```

Thus, due to incomplete information, a definitive answer can’t be provided directly from the given sets and functions.