Determine whether each pair of functions graphed are inverses.
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
3. Functions
Function Composition
Problem 21
Textbook Question
The functions in Exercises 11-28 are all one-to-one. For each function, a. Find an equation for f-1(x), the inverse function. b. Verify that your equation is correct by showing that f(ƒ-1 (x)) = = x and ƒ-1 (f(x)) = x. f(x) = 1/x
Verified step by step guidance1
Start with the given function: \(f(x) = \frac{1}{x}\). To find the inverse function \(f^{-1}(x)\), first replace \(f(x)\) with \(y\): \(y = \frac{1}{x}\).
Next, interchange the variables \(x\) and \(y\) to find the inverse: \(x = \frac{1}{y}\).
Now, solve this equation for \(y\) to express the inverse function explicitly. Multiply both sides by \(y\) to get \(xy = 1\), then divide both sides by \(x\) to isolate \(y\): \(y = \frac{1}{x}\).
Thus, the inverse function is \(f^{-1}(x) = \frac{1}{x}\). Notice that the function is its own inverse.
To verify, check the compositions: compute \(f(f^{-1}(x)) = f\left(\frac{1}{x}\right) = \frac{1}{\frac{1}{x}} = x\) and \(f^{-1}(f(x)) = f^{-1}\left(\frac{1}{x}\right) = \frac{1}{\frac{1}{x}} = x\). Both compositions return \(x\), confirming the inverse is correct.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
2mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
One-to-One Functions
A one-to-one function assigns each input exactly one unique output and vice versa, ensuring it has an inverse. This property is essential because only one-to-one functions have inverses that are also functions, allowing us to reverse the mapping from outputs back to inputs.
Recommended video:
Decomposition of Functions
Inverse Functions
The inverse of a function f, denoted f⁻¹, reverses the effect of f, swapping inputs and outputs. To find f⁻¹(x), solve the equation y = f(x) for x in terms of y, then interchange variables. The inverse satisfies f(f⁻¹(x)) = x and f⁻¹(f(x)) = x.
Recommended video:
Graphing Logarithmic Functions
Verification of Inverse Functions
To confirm that two functions are inverses, compose them in both orders: f(f⁻¹(x)) and f⁻¹(f(x)). Both compositions must simplify to x for all x in the domains. This step ensures the correctness of the inverse function found.
Recommended video:
Graphing Logarithmic Functions
Watch next
Master Function Composition with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Textbook Question
475
views
