Chapter 5: Problem 18
Graph the pair of functions on the same set of axes. $$y=3^{x} ; y=3^{-x}$$
Short Answer
Expert verified
Graph the functions, intersecting the y-axis at (0, 1), with \( y = 3^x \) showing growth and \( y = 3^{-x} \) showing decay.
Step by step solution
01
Understand the Function Types
The functions given are exponential. The first function, \( y = 3^x \), is an exponential growth function, while the second function, \( y = 3^{-x} \), is an exponential decay function. Both use base 3.
02
Create a Table for \( y = 3^x \)
Choose a set of x-values (e.g., -2, -1, 0, 1, 2) and calculate their corresponding y-values for the first function. For example:\[\begin{array}{c|c}x & y = 3^x \ \hline-2 & \frac{1}{9} \-1 & \frac{1}{3} \0 & 1 \1 & 3 \2 & 9 \\end{array}\]
03
Create a Table for \( y = 3^{-x} \)
Repeat the process for the second function with the same x-values:\[\begin{array}{c|c}x & y = 3^{-x} \ \hline-2 & 9 \-1 & 3 \0 & 1 \1 & \frac{1}{3} \2 & \frac{1}{9} \\end{array}\]
04
Plot the Points for \( y = 3^x \)
Using the table from Step 2, plot the points on the graph. These points are (-2, 1/9), (-1, 1/3), (0, 1), (1, 3), and (2, 9). Connect these points smoothly to show exponential growth.
05
Plot the Points for \( y = 3^{-x} \)
Now plot the points from the table in Step 3: (-2, 9), (-1, 3), (0, 1), (1, 1/3), and (2, 1/9). Connect these points smoothly to depict exponential decay.
06
Finalize the Graph
Ensure both functions are on the same set of axes and labeled clearly. Note that \( y = 3^x \) starts low and increases rapidly, while \( y = 3^{-x} \) starts high and decreases. Both intersect the y-axis at (0, 1).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Exponential Growth
In mathematics, exponential growth refers to a situation where the quantity increases rapidly over time. The function \( y = 3^x \) is a classic example of exponential growth. Here, the base of the exponential function is 3, which means each increase of 1 in the value of \( x \) results in the value of \( y \) being multiplied by 3.
Exponential growth functions are characterized by:
Exponential growth functions are characterized by:
- A rapid increase in the value of \( y \) as \( x \) becomes larger.
- Y-values that are positive for all real numbers \( x \).
- A curve that moves upwards steeply as it progresses from left to right.
- A horizontal asymptote at y = 0, meaning as \( x \) approaches negative infinity, \( y \) approaches zero.
Exponential Decay
Exponential decay describes a process where the value decreases rapidly as time goes on. The function \( y = 3^{-x} \) represents exponential decay. Here, the negative exponent signifies that as \( x \) increases, the value of \( y \) diminishes at an accelerating rate.
Some key characteristics of exponential decay include:
Some key characteristics of exponential decay include:
- The value of \( y \) shrinks toward zero as \( x \) gets larger.
- The graph is a mirrored version of exponential growth across the y-axis.
- It features a downward slope with the curve flattening as it approaches zero.
- Similarly, it also has a horizontal asymptote at y = 0.
Graphing Functions
Graphing functions is a powerful way to visualize and understand mathematical relationships. For the functions \( y = 3^x \) and \( y = 3^{-x} \), the graph shows us clear distinctions between exponential growth and decay.
Graphing involves these steps:
Graphing involves these steps:
- Choose a reasonable range of \( x \)-values. In our case, using -2, -1, 0, 1, 2 helps visualize both growth and decay.
- Calculate corresponding \( y \)-values, which are gained from substituting each \( x \)-value into the function equation.
- Plot each point (\( x, y \)) on a Cartesian plane for both functions.
- Connect the points smoothly to reveal the function's curve.