Math Problem Statement
Show all the work for this problem. determine whether this function has an inverse function. 1.) y = 3/x-2 - 1 2.)y = x^3 -4x +6 3.) y = ln x^2
Solution
Let's analyze each function to determine whether it has an inverse. For a function to have an inverse, it must be one-to-one. This means that each value of is associated with exactly one value of . We'll use the horizontal line test and the derivative test where applicable.
1. Function:
Step 1: Analyze the Function
- This function is a transformation of the basic rational function .
- The function is a horizontal stretch by a factor of 3 and a horizontal shift to the right by 2 units.
- The subtraction of 1 indicates a downward shift by 1 unit.
Step 2: Determine if the Function is One-to-One
- To check if the function is one-to-one, let's rewrite the equation in terms of and solve for .
Starting with:
Add 1 to both sides:
Now multiply both sides by :
Distribute :
Solve for :
Since we can solve for uniquely in terms of , the function is one-to-one.
Conclusion: The function has an inverse function.
2. Function:
Step 1: Analyze the Function
- The function is a cubic polynomial, which is generally continuous and smooth.
Step 2: Determine if the Function is One-to-One
- Let's check the derivative to determine whether the function is strictly increasing or decreasing.
The derivative is:
Step 3: Analyze the Derivative
- Set the derivative equal to zero to find the critical points:
Solving for :
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The function changes its slope at these points, which means the function is not strictly increasing or decreasing over its entire domain.
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Since the function can have the same value for different values, it fails the horizontal line test.
Conclusion: The function does not have an inverse function.
3. Function:
Step 1: Analyze the Function
- This function involves the natural logarithm of .
- Let's rewrite the function:
Step 2: Determine if the Function is One-to-One
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Since , the function is not one-to-one because takes the same value for both positive and negative .
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For example, and give the same value, which means it fails the horizontal line test.
Conclusion: The function does not have an inverse function.
Would you like further details or have any other questions about these problems?
Here are 5 related questions to explore:
- How does the derivative help determine if a function is one-to-one?
- What is the general form of the inverse of a linear function?
- Can a function be one-to-one on a restricted domain even if it’s not one-to-one overall?
- How does the horizontal line test work in determining the existence of an inverse?
- What are the characteristics of logarithmic functions and their inverses?
Tip: Always consider the domain of the function when determining if it is one-to-one; different domains can change whether a function has an inverse!
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Math Problem Analysis
Mathematical Concepts
Functions
Inverse Functions
Horizontal Line Test
Derivative Test
Formulas
Derivative of a function
Theorems
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Suitable Grade Level
Advanced High School