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Ch. 2 - Functions and Graphs
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 3, Problem 49abc

In Exercises 39-52, a. Find an equation for ƒ¯¹(x). b. Graph ƒ and ƒ¯¹(x) in the same rectangular coordinate system. c. Use interval notation to give the domain and the range off and ƒ¯¹. f(x) = √(x-1)

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Step 1: To find the inverse function ƒ¯¹(x), start by replacing f(x) with y. This gives y = √(x - 1). Next, swap x and y to reflect the inverse relationship. This results in x = √(y - 1).
Step 2: Solve for y in terms of x to find the inverse function. Square both sides of the equation to eliminate the square root: x² = y - 1. Then, isolate y by adding 1 to both sides: y = x² + 1. Thus, the inverse function is ƒ¯¹(x) = x² + 1.
Step 3: To graph both f(x) and ƒ¯¹(x), plot f(x) = √(x - 1), which is a square root function starting at x = 1 and increasing to the right. For ƒ¯¹(x) = x² + 1, plot a parabola that opens upwards with its vertex at (0, 1). Ensure both graphs are in the same rectangular coordinate system.
Step 4: Determine the domain and range of f(x). Since f(x) = √(x - 1), the domain is [1, ∞) because the square root function is only defined for x - 1 ≥ 0. The range is [0, ∞) because the square root function outputs non-negative values.
Step 5: Determine the domain and range of ƒ¯¹(x). Since ƒ¯¹(x) = x² + 1, the domain is [0, ∞) because the input to the inverse function corresponds to the range of f(x). The range of ƒ¯¹(x) is [1, ∞) because the output of the inverse function corresponds to the domain of f(x).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Inverse Functions

An inverse function reverses the effect of the original function. For a function f(x), its inverse f¯¹(x) satisfies the condition f(f¯¹(x)) = x for all x in the domain of f¯¹. To find the inverse, one typically swaps the roles of x and y in the equation and solves for y.
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Domain and Range

The domain of a function is the set of all possible input values (x-values) that the function can accept, while the range is the set of all possible output values (y-values) that the function can produce. Understanding the domain and range is crucial for both the original function and its inverse, as they are interchanged in inverse functions.
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Graphing Functions

Graphing functions involves plotting points on a coordinate system to visually represent the relationship between the input and output values. When graphing both a function and its inverse, the graphs will be symmetric with respect to the line y = x, illustrating how each function undoes the other.
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