Describing the End Behavior

Oct 13, 2025 by wbrum.org 31 views

The given function is $f(x)=7\left(\frac{1}{3}\right)^x+2$ . To identify the $y$ -intercept, we need to find the value of the function when $x=0$ . The $y$ -intercept is the point where the graph of the function crosses the $y$ -axis.

Finding the $y$ -Intercept

To find the $y$ -intercept, we substitute $x=0$ into the function:

$f(0)=7\left(\frac{1}{3}\right)^0+2$

Since $\left(\frac{1}{3}\right)^0=1$ , we have:

$f(0)=7(1)+2$

$f(0)=9$

Therefore, the $y$ -intercept is $(0,9)$ .

Describing the End Behavior

To describe the end behavior of the function, we need to analyze the behavior of the function as $x$ approaches positive infinity and negative infinity.

As $x$ Approaches Positive Infinity

As $x$ approaches positive infinity, the term $\left(\frac{1}{3}\right)^x$ approaches zero. This is because the base $\frac{1}{3}$ is less than 1, and as the exponent $x$ increases, the value of the term decreases.

Since the term $\left(\frac{1}{3}\right)^x$ approaches zero, the function $f(x)$ approaches the value of the constant term, which is 2. Therefore, as $x$ approaches positive infinity, the function $f(x)$ approaches 2.

As $x$ Approaches Negative Infinity

As $x$ approaches negative infinity, the term $\left(\frac{1}{3}\right)^x$ approaches infinity. This is because the base $\frac{1}{3}$ is less than 1, and as the exponent $x$ decreases, the value of the term increases.

Since the term $\left(\frac{1}{3}\right)^x$ approaches infinity, the function $f(x)$ also approaches infinity. Therefore, as $x$ approaches negative infinity, the function $f(x)$ approaches infinity.

Conclusion

In conclusion, the $y$ -intercept of the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ is $(0,9)$ . The end behavior of the function is that as $x$ approaches positive infinity, the function approaches 2, and as $x$ approaches negative infinity, the function approaches infinity.

Graphing the Function

To visualize the function, we can graph it using a graphing calculator or a computer algebra system. The graph of the function will be a curve that passes through the point $(0,9)$ and approaches 2 as $x$ approaches positive infinity, and approaches infinity as $x$ approaches negative infinity.

Key Takeaways

The $y$ -intercept of the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ is $(0,9)$ .
As $x$ approaches positive infinity, the function approaches 2.
As $x$ approaches negative infinity, the function approaches infinity.

Real-World Applications

The function $f(x)=7\left(\frac{1}{3}\right)^x+2$ has several real-world applications. For example, it can be used to model population growth or decay, where the base $\frac{1}{3}$ represents the rate of growth or decay, and the exponent $x$ represents time.

Solving Equations

The function $f(x)=7\left(\frac{1}{3}\right)^x+2$ can also be used to solve equations. For example, if we want to find the value of $x$ that satisfies the equation $f(x)=10$ , we can substitute $f(x)=10$ into the function and solve for $x$ .

Exercises

Find the $y$ -intercept of the function $f(x)=5\left(\frac{1}{2}\right)^x+3$ .
Describe the end behavior of the function $f(x)=3\left(\frac{1}{4}\right)^x+1$ .
Graph the function $f(x)=2\left(\frac{1}{5}\right)^x+4$ and describe its end behavior.

Answer Key

The $y$ -intercept is $(0,8)$ .
As $x$ approaches positive infinity, the function approaches 1. As $x$ approaches negative infinity, the function approaches infinity.
The graph of the function will be a curve that passes through the point $(0,6)$ and approaches 4 as $x$ approaches positive infinity, and approaches infinity as $x$ approaches negative infinity.
Q&A: Understanding the Function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ===========================================================

Q: What is the $y$ -intercept of the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ?

A: The $y$ -intercept of the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ is $(0,9)$ .

Q: What happens to the function as $x$ approaches positive infinity?

A: As $x$ approaches positive infinity, the term $\left(\frac{1}{3}\right)^x$ approaches zero. Therefore, the function $f(x)$ approaches the value of the constant term, which is 2.

Q: What happens to the function as $x$ approaches negative infinity?

A: As $x$ approaches negative infinity, the term $\left(\frac{1}{3}\right)^x$ approaches infinity. Therefore, the function $f(x)$ also approaches infinity.

Q: Can you graph the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ?

A: Yes, the graph of the function will be a curve that passes through the point $(0,9)$ and approaches 2 as $x$ approaches positive infinity, and approaches infinity as $x$ approaches negative infinity.

Q: What are some real-world applications of the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ?

A: The function $f(x)=7\left(\frac{1}{3}\right)^x+2$ has several real-world applications, including modeling population growth or decay, where the base $\frac{1}{3}$ represents the rate of growth or decay, and the exponent $x$ represents time.

Q: How can you use the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ to solve equations?

A: You can use the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ to solve equations by substituting the value of the function into the equation and solving for $x$ .

Q: What are some exercises that can help you understand the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ?

A: Some exercises that can help you understand the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ include:

Finding the $y$ -intercept of the function $f(x)=5\left(\frac{1}{2}\right)^x+3$ .
Describing the end behavior of the function $f(x)=3\left(\frac{1}{4}\right)^x+1$ .
Graphing the function $f(x)=2\left(\frac{1}{5}\right)^x+4$ and describing its end behavior.

Q: What is the answer key for the exercises?

A: The answer key for the exercises is:

The $y$ -intercept is $(0,8)$ .
As $x$ approaches positive infinity, the function approaches 1. As $x$ approaches negative infinity, the function approaches infinity.
The graph of the function will be a curve that passes through the point $(0,6)$ and approaches 4 as $x$ approaches positive infinity, and approaches infinity as $x$ approaches negative infinity.

Q: Can you provide more information about the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ ?

A: Yes, the function $f(x)=7\left(\frac{1}{3}\right)^x+2$ is a type of exponential function that has a base of $\frac{1}{3}$ and an exponent of $x$ . The function has a $y$ -intercept of $(0,9)$ and approaches 2 as $x$ approaches positive infinity, and approaches infinity as $x$ approaches negative infinity. The function has several real-world applications, including modeling population growth or decay, and can be used to solve equations by substituting the value of the function into the equation and solving for $x$ .