Chapter 5: Problem 16
List the transformations needed to transform the graph of \(h(x)=2^{x}\) into the graph of the given function. $$g(x)=-5\left(2^{x-1}\right)+7$$
Short Answer
Expert verified
Answer: The transformations needed include a horizontal shift of 1 unit to the right, a vertical stretch by a factor of 5, a reflection across the x-axis, and a vertical shift of 7 units up.
Step by step solution
01
Identify the base function
The base function here is h(x) = 2^x, an exponential function. We need to transform this function to get the desired function, g(x) = -5(2^(x-1)) + 7.
02
Identify horizontal shift
The given function is g(x) = -5(2^(x-1)) + 7. We can see that the exponent has been modified from x to (x-1). This is a horizontal shift of 1 unit to the right. So we write it as: Horizontal Shift = 1 unit to the right.
03
Identify vertical stretch/compression
Since the base function h(x) has been multiplied by -5, there is a vertical stretch by a factor of 5. This means that the graph of g(x) is 5 times taller than the graph of the base function h(x). So we write it as: Vertical Stretch/Compression = times 5.
04
Identify reflection
Because the -5 in g(x) = -5(2^(x-1)) + 7 is a negative value, there is a reflection across the x-axis. This change causes the graph to be flipped over the x-axis. So we write it as: Reflection across x-axis.
05
Identify vertical shift
In the given function, g(x) = -5(2^(x-1)) + 7, there is an added term of +7. This means that the graph has been shifted vertically up by 7 units. So we write it as: Vertical Shift = 7 units up.
Now, putting all the transformations together, we can describe the process of transforming the graph of h(x) = 2^x into the graph of g(x) = -5(2^(x-1)) + 7 as follows:
1. Horizontal Shift: 1 unit to the right
2. Vertical Stretch/Compression: times 5
3. Reflection: across x-axis
4. Vertical Shift: 7 units up
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.
Horizontal Shift
A horizontal shift refers to the movement of a graph along the x-axis. In the transformation of the function \(h(x) = 2^x\) into \(g(x) = -5(2^{x-1}) + 7\), we notice the change in the exponent from \(x\) to \(x-1\). This indicates a horizontal shift to the right.
- The "-1" inside the exponent means we are translating 1 unit to the right.
- This shift is crucial as it affects where the graph starts along the x-axis.
Vertical Stretch
A vertical stretch occurs when you multiply the function by a certain factor. In this instance, the original function, \(h(x) = 2^x\), is multiplied by -5, creating \(g(x) = -5(2^{x-1}) + 7\).
- This transformation scales the graph vertically by a factor of 5.
- Simply put, it makes the graph 5 times taller.
Reflection
Reflection refers to flipping a graph across a specific axis. In the function \(g(x) = -5(2^{x-1}) + 7\), the negative sign in front of the 5 indicates a reflection over the x-axis.
- This transformation inverts points on the graph of \(h(x) = 2^x\) downwards.
- All y-values of the graph change their signs due to this flip.
Vertical Shift
Vertical shifts are easier to spot as they involve adding or subtracting a constant outside the function. In the transformation from \(h(x) = 2^x\) to \(g(x) = -5(2^{x-1}) + 7\), the "+7" indicates a vertical shift upwards.
- Every point on the graph of the base function moves up by 7 units.
- It increases the height of the entire graph by a consistent amount, no matter the input \(x\).