Exercises 123–125 will help you prepare for the material covered in the next section. Solve for y: x = y² -1, y ≥ 0.
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 27
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) = (2x +1)/(x-3)
Verified step by step guidance1
Start by writing the function as an equation with y: \(y = \frac{2x + 1}{x - 3}\).
To find the inverse, swap x and y: \(x = \frac{2y + 1}{y - 3}\).
Solve this new equation for y. Begin by multiplying both sides by \((y - 3)\) to eliminate the denominator: \(x(y - 3) = 2y + 1\).
Distribute x on the left side: \(xy - 3x = 2y + 1\). Then, collect all terms involving y on one side and constants on the other: \(xy - 2y = 3x + 1\).
Factor y out on the left side: \(y(x - 2) = 3x + 1\). Finally, solve for y by dividing both sides by \((x - 2)\): \(y = \frac{3x + 1}{x - 2}\). This y represents the inverse function \(f^{-1}(x)\).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
6mPlay 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 function is one-to-one if each output corresponds to exactly one input, meaning it passes the horizontal line test. This property ensures the function has an inverse because no two different inputs produce the same output, allowing the inverse to be well-defined.
Recommended video:
Decomposition of Functions
Finding the Inverse Function
To find the inverse of a function, swap the roles of x and y in the equation and solve for y. This process reverses the input-output relationship, producing a function that 'undoes' the original function's operation.
Recommended video:
Graphing Logarithmic Functions
Verification of Inverse Functions
To verify an inverse function, compose the original function with its inverse in both orders: f(f⁻¹(x)) and f⁻¹(f(x)). Both compositions should simplify to x, confirming that the functions are true inverses of each other.
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
451
views
