The function [tex]$f$[/tex] is defined as follows:

[tex]\[
f(x)=\left\{
\begin{array}{ll}
2x & \text{if } x \neq 0 \\
3 & \text{if } x = 0
\end{array}
\right.
\][/tex]

(a) Find the domain of the function.
(b) Locate any intercepts.
(c) Graph the function.
(d) Based on the graph, find the range.

(a) The domain of the function [tex]$f$[/tex] is [tex]\square[/tex].
(Type your answer in interval notation.)



Answer :

Let's solve the problem step-by-step based on the given function [tex]\( f \)[/tex]:

### (a) Finding the Domain of the Function
The domain of a function is the set of all possible values of [tex]\( x \)[/tex] for which the function is defined. For the given function:
[tex]\[ f(x) = \begin{cases} 2x & \text{if } x \neq 0 \\ 3 & \text{if } x = 0 \end{cases} \][/tex]
The function [tex]\( f \)[/tex] is defined for all real numbers [tex]\( x \)[/tex]. There are no restrictions on [tex]\( x \)[/tex] since the function provides values for every possible [tex]\( x \)[/tex], whether [tex]\( x = 0 \)[/tex] or [tex]\( x \neq 0 \)[/tex].

So, the domain of the function [tex]\( f \)[/tex] is:
[tex]\[ \boxed{(-\infty, \infty)} \][/tex]

### (b) Locating the Intercepts
Y-Intercept:
The y-intercept is the point where [tex]\( x = 0 \)[/tex]. Substituting [tex]\( x = 0 \)[/tex] into the function:
[tex]\[ f(0) = 3 \][/tex]
Thus, the y-intercept is:
[tex]\[ \boxed{3} \][/tex]

X-Intercept:
The x-intercept is the point where [tex]\( f(x) = 0 \)[/tex]. For [tex]\( f(x) = 0 \)[/tex]:
[tex]\[ \begin{cases} 2x = 0 & \text{if } x \neq 0 \\ 3 = 0 & \text{if } x = 0 \end{cases} \][/tex]
For [tex]\( x \neq 0 \)[/tex], solving [tex]\( 2x = 0 \)[/tex] gives [tex]\( x = 0 \)[/tex], but at [tex]\( x = 0 \)[/tex], [tex]\( f(x) = 3 \neq 0 \)[/tex]. Therefore, there is no valid [tex]\( x \)[/tex] for which [tex]\( f(x) = 0 \)[/tex].

Thus, there are no x-intercepts:
[tex]\[ \boxed{\text{None}} \][/tex]

### (c) Graphing the Function
To graph the function, we consider the two cases:
1. When [tex]\( x \neq 0 \)[/tex], the graph of [tex]\( f(x) = 2x \)[/tex] is a straight line passing through the origin with a slope of 2.
2. At [tex]\( x = 0 \)[/tex], the function takes the value [tex]\( f(0) = 3 \)[/tex]. This is a point away from the line [tex]\( 2x \)[/tex].

Here's a rough sketch of the graph:

- For [tex]\( x \neq 0 \)[/tex], the line [tex]\( y = 2x \)[/tex] is drawn except at [tex]\( x = 0 \)[/tex].
- At [tex]\( x = 0 \)[/tex], there's an isolated point [tex]\((0, 3)\)[/tex].

### (d) Finding the Range
The range of a function is the set of all possible values of [tex]\( f(x) \)[/tex] that the function can take. From the function behavior:
- When [tex]\( x \neq 0 \)[/tex], [tex]\( f(x) = 2x \)[/tex] can take any value from [tex]\( -\infty \)[/tex] to [tex]\( \infty \)[/tex] except at 0.
- At [tex]\( x = 0 \)[/tex], [tex]\( f(x) = 3 \)[/tex].

Thus, the range of the function [tex]\( f \)[/tex] is all real numbers except at the value 0:
[tex]\[ \boxed{(-\infty, 0) \cup (0, \infty)} \][/tex]

This completes the thorough step-by-step solution to the given problem.