An exponential function f(x) = ab passes through the points (0, 4) and (3, 108). What are the values of a and b? a = b =

Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter6: Vector Spaces
Section6.7: Applications
Problem 16EQ
icon
Related questions
Question
### Understanding Exponential Functions

An exponential function is a mathematical expression in the form \( f(x) = ab^x \), where:
- \( a \) is a constant that represents the initial amount (when \( x = 0 \)).
- \( b \) is the base of the exponential, representing the growth factor if \( b > 1 \) or the decay factor if \( 0 < b < 1 \).
- \( x \) is the variable.

#### Example Problem:

Determine the values of \( a \) and \( b \) for the exponential function \( f(x) = ab^x \) that passes through the points \( (0, 4) \) and \( (3, 108) \).

To solve this, follow these steps:

1. **Substitute the points into the function:**

    For the point \( (0, 4) \):
    \[ 4 = ab^0 \]
    \[ 4 = a \cdot 1 \]
    \[ a = 4 \]

    For the point \( (3, 108) \):
    \[ 108 = 4b^3 \]

2. **Solve for \( b \):**
    \[ 108 = 4b^3 \]
    \[ b^3 = \frac{108}{4} \]
    \[ b^3 = 27 \]
    \[ b = \sqrt[3]{27} \]
    \[ b = 3 \]

Therefore, the values are:
\[ a = 4 \]
\[ b = 3 \]

### Input Section

Please enter the values of \( a \) and \( b \) in the boxes provided below:
```
a = [    ]
b = [    ]
```

**Question Help:**
For more assistance, click on the video link below:
[![Video](video_link_placeholder)](video_link)

### Explanation:

- The **initial point (0, 4)** helps determine the value of \( a \).
- The **second point (3, 108)** helps to solve for \( b \) when substituted back into the function after solving for \( a \).
- The function \( f(x) \) is completely defined once the values of \( a \) and \( b \) are known.

This foundational understanding of exponential functions is critical for algebra and pre
Transcribed Image Text:### Understanding Exponential Functions An exponential function is a mathematical expression in the form \( f(x) = ab^x \), where: - \( a \) is a constant that represents the initial amount (when \( x = 0 \)). - \( b \) is the base of the exponential, representing the growth factor if \( b > 1 \) or the decay factor if \( 0 < b < 1 \). - \( x \) is the variable. #### Example Problem: Determine the values of \( a \) and \( b \) for the exponential function \( f(x) = ab^x \) that passes through the points \( (0, 4) \) and \( (3, 108) \). To solve this, follow these steps: 1. **Substitute the points into the function:** For the point \( (0, 4) \): \[ 4 = ab^0 \] \[ 4 = a \cdot 1 \] \[ a = 4 \] For the point \( (3, 108) \): \[ 108 = 4b^3 \] 2. **Solve for \( b \):** \[ 108 = 4b^3 \] \[ b^3 = \frac{108}{4} \] \[ b^3 = 27 \] \[ b = \sqrt[3]{27} \] \[ b = 3 \] Therefore, the values are: \[ a = 4 \] \[ b = 3 \] ### Input Section Please enter the values of \( a \) and \( b \) in the boxes provided below: ``` a = [ ] b = [ ] ``` **Question Help:** For more assistance, click on the video link below: [![Video](video_link_placeholder)](video_link) ### Explanation: - The **initial point (0, 4)** helps determine the value of \( a \). - The **second point (3, 108)** helps to solve for \( b \) when substituted back into the function after solving for \( a \). - The function \( f(x) \) is completely defined once the values of \( a \) and \( b \) are known. This foundational understanding of exponential functions is critical for algebra and pre
Expert Solution
steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Recommended textbooks for you
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781337278461
Author:
Ron Larson
Publisher:
Cengage Learning
College Algebra
College Algebra
Algebra
ISBN:
9781337282291
Author:
Ron Larson
Publisher:
Cengage Learning
Calculus For The Life Sciences
Calculus For The Life Sciences
Calculus
ISBN:
9780321964038
Author:
GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Publisher:
Pearson Addison Wesley,
Algebra & Trigonometry with Analytic Geometry
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage