Consider the graph of the function [tex]f(x)=\left(\frac{1}{4}\right)^x[/tex].

Which statements describe key features of function [tex]f[/tex]?

A. Range of [tex]\{y \mid 0\ \textless \ y\ \textless \ \infty\}[/tex]
B. Horizontal asymptote of [tex]y=0[/tex]
C. Domain of [tex]\{x \mid -\infty\ \textless \ x\ \textless \ \infty\}[/tex]
D. [tex]y[/tex]-intercept at [tex](0,1)[/tex]



Answer :

Let's analyze the function [tex]\( f(x) = \left(\frac{1}{4}\right)^x \)[/tex] and its key features step-by-step.

### 1. Range of the function

To determine the range, we need to understand the behavior of [tex]\( f(x) \)[/tex] as [tex]\( x \)[/tex] varies.

- As [tex]\( x \to \infty \)[/tex], the expression [tex]\( \left(\frac{1}{4}\right)^x \)[/tex] approaches 0 because [tex]\( \frac{1}{4} \)[/tex] is a positive fraction less than 1.
- As [tex]\( x \to -\infty \)[/tex], the expression [tex]\( \left(\frac{1}{4}\right)^x \)[/tex] grows larger without bound (approaching [tex]\( \infty \)[/tex]).
- Since [tex]\( \left(\frac{1}{4}\right)^x \)[/tex] is always positive for all real [tex]\( x \)[/tex], it never equals zero or negative.

Thus, the range of the function [tex]\( f(x) = \left(\frac{1}{4}\right)^x \)[/tex] is [tex]\((0, \infty)\)[/tex], meaning [tex]\( 0 < y < \infty \)[/tex].

### 2. Horizontal asymptote

The horizontal asymptote of a function describes the value that the function approaches as [tex]\( x \)[/tex] tends to [tex]\( \infty \)[/tex] or [tex]\( -\infty \)[/tex].

- As [tex]\( x \to \infty \)[/tex], [tex]\( \left(\frac{1}{4}\right)^x \to 0 \)[/tex].

Hence, the horizontal asymptote of [tex]\( f(x) \)[/tex] is [tex]\( y = 0 \)[/tex].

### 3. Domain of the function

The domain of a function is the complete set of possible values of the independent variable [tex]\( x \)[/tex].

- The function [tex]\( \left(\frac{1}{4}\right)^x \)[/tex] is defined for all real numbers [tex]\( x \)[/tex].

Therefore, the domain of [tex]\( f(x) = \left(\frac{1}{4}\right)^x \)[/tex] is [tex]\(\{x \mid -\infty < x < \infty \}\)[/tex].

### 4. [tex]\( y \)[/tex]-intercept

The [tex]\( y \)[/tex]-intercept occurs when [tex]\( x = 0 \)[/tex]. We substitute [tex]\( x = 0 \)[/tex] into the function to find the corresponding [tex]\( y \)[/tex]-value:

[tex]\[ f(0) = \left(\frac{1}{4}\right)^0 = 1 \][/tex]

Therefore, the [tex]\( y \)[/tex]-intercept is [tex]\( (0, 1) \)[/tex].

### Conclusion

Summarizing the key features of the function [tex]\( f(x) = \left(\frac{1}{4}\right)^x \)[/tex]:

- The range of [tex]\( f(x) \)[/tex] is [tex]\(\{ y \mid 0 < y < \infty \}\)[/tex].
- The horizontal asymptote is [tex]\( y = 0 \)[/tex].
- The domain of [tex]\( f(x) \)[/tex] is [tex]\( \{ x \mid -\infty < x < \infty \} \)[/tex].
- The [tex]\( y \)[/tex]-intercept is at [tex]\( (0, 1) \)[/tex].

Thus, the statements that describe the key features of the function [tex]\( f(x) = \left(\frac{1}{4}\right)^x \)[/tex] are:

- Range of [tex]\( \{ y \mid 0 < y < \infty \} \)[/tex]
- Horizontal asymptote of [tex]\( y = 0 \)[/tex]
- Domain of [tex]\( \{ x \mid -\infty < x < \infty \} \)[/tex] (corrected from [tex]\(\{x \mid -1- [tex]\( y \)[/tex]-intercept at [tex]\( (0, 1) \)[/tex]

It should be noted that there was an error in the original statement regarding the domain, which should be corrected to [tex]\(-\infty < x < \infty\)[/tex].