IDNLearn.com makes it easy to get reliable answers from experts and enthusiasts alike. Find accurate and detailed answers to your questions from our experienced and dedicated community members.

If [tex]$f(x) = (x+1)^{-1}$[/tex] and [tex]$g(x) = x-2$[/tex], what is the domain of [tex]$f(x) \div g(x)$[/tex]?

A. all values of [tex]$x$[/tex]

B. [tex]$(-\infty, -1) \cup (-1, 2) \cup (2, \infty)$[/tex]

C. [tex]$(-\infty, 2) \cup (2, \infty)$[/tex]

D. [tex]$(-\infty, -1] \cup [2, \infty)$[/tex]


Sagot :

To determine the domain of the function [tex]\( \frac{f(x)}{g(x)} \)[/tex] where [tex]\( f(x) = \frac{1}{x+1} \)[/tex] and [tex]\( g(x) = x-2 \)[/tex], we need to consider where both functions are well-defined and where the overall expression is defined.

1. Identify the domain of [tex]\( f(x) \)[/tex]:
[tex]\( f(x) = \frac{1}{x+1} \)[/tex]. This function is undefined where the denominator is zero:
[tex]\[ x + 1 = 0 \implies x = -1 \][/tex]
Therefore, [tex]\( f(x) \)[/tex] is undefined at [tex]\( x = -1 \)[/tex]. So the domain of [tex]\( f(x) \)[/tex] is all real numbers except [tex]\( x = -1 \)[/tex]:
[tex]\[ \text{Domain of } f(x) = \{ x \in \mathbb{R} : x \neq -1 \} \][/tex]

2. Identify the domain of [tex]\( g(x) \)[/tex]:
[tex]\( g(x) = x - 2 \)[/tex]. This is a linear function and it is defined for all real numbers:
[tex]\[ \text{Domain of } g(x) = \mathbb{R} \][/tex]

3. Identify where [tex]\( g(x) = 0 \)[/tex]:
[tex]\[ x - 2 = 0 \implies x = 2 \][/tex]
For the function [tex]\( \frac{f(x)}{g(x)} = \frac{\frac{1}{x+1}}{x-2} = \frac{1}{(x+1)(x-2)} \)[/tex], it will be undefined not only where [tex]\( f(x) \)[/tex] or [tex]\( g(x) \)[/tex] are undefined, but also where [tex]\( g(x) = 0 \)[/tex].

4. Combine the constraints:
We need [tex]\( x \neq -1 \)[/tex] and [tex]\( x \neq 2 \)[/tex]. So, combining these, the domain of [tex]\( \frac{f(x)}{g(x)} \)[/tex] is:
[tex]\[ \{ x \in \mathbb{R} : x \neq -1 \text{ and } x \neq 2 \} \][/tex]

In interval notation, this is expressed as:
[tex]\[ (-\infty, -1) \cup (-1, 2) \cup (2, \infty) \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{B. (-\infty, -1), (-1, 2), \text{ and } (2, \infty)} \][/tex]
Thank you for joining our conversation. Don't hesitate to return anytime to find answers to your questions. Let's continue sharing knowledge and experiences! Thank you for visiting IDNLearn.com. We’re here to provide clear and concise answers, so visit us again soon.