Chapter 3: Problem 41
Graph the exponential function using transformations. State the \(y\) -intercept, two additional points, the domain, the range, and the horizontal asymptote. $$f(x)=e^{x+1}-4$$
Short Answer
Expert verified
The y-intercept is (0, -1.282), with additional points (1, 3.389) and (-1, -3). The domain is all real numbers, the range is (-4, ∞), and the horizontal asymptote is y = -4.
Step by step solution
01
Identify the Base Function
The base function for transformations is the exponential function \(f(x) = e^x\). The graph of \(f(x) = e^x\) passes through the point \((0, 1)\) and has a horizontal asymptote at \(y = 0\).
02
Apply Horizontal Transformation
The expression \(e^{x+1}\) represents a horizontal shift to the left by 1 unit of the base function \(e^x\). To verify, note that if \( f(x) = e^x\), then \(f(x+1) = e^{x+1}\) will shift the graph leftwards.
03
Apply Vertical Transformation
The subtraction of 4, i.e., \(-4\) in \(f(x) = e^{x+1} - 4\), is a vertical shift downwards by 4 units. Thus, the entire graph of \(e^{x+1}\) is lowered by 4 units.
04
State the Transformed y-intercept
For the y-intercept, set \(x = 0\) and compute: \[ f(0) = e^{0+1} - 4 = e^1 - 4 \approx 2.718 - 4 = -1.282.\]Thus, the y-intercept is \((0, -1.282)\).
05
Determine Two Additional Points
Choose two other values of \(x\) to find additional points:1. For \(x=1\), \[ f(1) = e^{1+1} - 4 = e^2 - 4 \approx 7.389 - 4 = 3.389. \] Thus, the point is \((1, 3.389)\).2. For \(x=-1\), \[ f(-1) = e^{-1+1} - 4 = e^0 - 4 = 1 - 4 = -3. \] Thus, the point is \((-1, -3)\).
06
State the Domain and Range
The domain of an exponential function is all real numbers, or \((-f, f )\). The vertical shift affects the range, making it \((-4, f)\).
07
Identify the Horizontal Asymptote
The horizontal shift does not affect the asymptote. However, the vertical shift downward by 4 units moves the asymptote from \(y = 0\) to \(y = -4\).
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.
Graphing Transformations
Graphing transformations involves shifting, stretching, or reflecting a graph compared to its base function. Here, we work with the exponential function, which has unique properties that make transformations straightforward yet important.
- Horizontal shifts move the graph left or right.
- Vertical shifts move the graph up or down.
- Reflections flip the graph over a specific axis.
Domain and Range
Understanding the domain and range of a function helps us comprehend where the function is defined and the values it can take.
- The **domain** of exponential functions like \( f(x) = e^x \) is all real numbers, symbolized by \( (-\infty, \infty) \).
- The **range** is transformed by vertical shifts. For our function, the transformation shifted the graph downward. As a result, the range changes from \( (0, \infty) \) to \( (-4, \infty) \).
Horizontal Asymptote
An exponential function generally approaches a horizontal line, known as an asymptote, as it progresses towards extremes on the x-axis.
- For the base function \( f(x) = e^x \), the horizontal asymptote is at \( y = 0 \).
- The vertical transformation affects the horizontal asymptote.For our function, it shifts down 4 units, from \( y = 0 \) to \( y = -4 \).
Exponential Functions
Exponential functions, such as \( f(x) = e^x \), describe rapid growth or decay processes, frequently occurring in real-world applications.Key features of exponential functions include:
- **Base Value**: The constant \( e \) is approximately 2.718, a natural exponential base widely used in mathematics and other scientific applications.
- **Growth Pattern**: The graph of an exponential function steadily increases (for positive exponents) or decreases (for negative exponents).
- **Transformations**: They can undergo various transformations which alter their graph, including shifting and reflecting. This transforms the behavior while preserving the primary exponential nature.