/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 32 Find the inverse function (on th... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the inverse function (on the given interval, if specified) and graph both fand \(f^{-1}\) on the same set of axes. Check your work by looking for the required symmetry in the graphs. $$f(x)=8-4 x$$

Short Answer

Expert verified
Answer: The inverse function of \(f(x) = 8 - 4x\) is \(f^{-1}(x) = 2 - \frac{x}{4}\). When graphing both functions on the same set of axes, the graphs are symmetric with respect to the line \(y = x\), indicating that they are indeed inverses of each other.

Step by step solution

01

Find the inverse function of \(f(x)\)

To find the inverse function of \(f(x) = 8 - 4x\), we will switch the roles of \(x\) and \(y\) and then solve for \(y\). Let \(y = 8 - 4x\). Therefore, the inverse function can be found by solving the equation \(x = 8 - 4y\) for \(y\): 1. Add \(4y\) to both sides: \(x + 4y = 8\) 2. Subtract \(x\) from both sides: \(4y = 8 - x\) 3. Divide both sides by 4: \(y = \frac{8-x}{4} = 2 - \frac{x}{4}\) Therefore, the inverse function, \(f^{-1}(x)\), is given by: $$f^{-1}(x) = 2 - \frac{x}{4}$$
02

Graphing the functions

To graph both functions, \(f(x) = 8 - 4x\) and \(f^{-1}(x) = 2 - \frac{x}{4}\), we start by creating a table for each function, noting their respective x- and y-coordinates. For \(f(x) = 8 - 4x\): \(x\) | \(f(x)\) --------|------- 0 | 8 1 | 4 2 | 0 For \(f^{-1}(x) = 2 - \frac{x}{4}\): \(x\) | \(f^{-1}(x)\) --------|------- 0 | 2 4 | 1 8 | 0 Next, plot the sets of points for both functions on the same set of axes and draw the lines that represent the functions. Finally, check for symmetry by plotting the line \(y = x\). If the functions are inverses, their graphs will be mirror images of each other through the line \(y = x\). If that is the case, we can be confident that we found the correct inverse function and graphed it properly.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Graphing Functions
Graphing functions is a way to visualize the relationship between input and output values of a function by plotting points on a coordinate plane. It helps in understanding how the function behaves across different values of its variables. To graph functions like \(f(x) = 8 - 4x\) and its inverse \(f^{-1}(x) = 2 - \frac{x}{4}\), you should start by creating a table of values.
  • Choose a few values of \(x\), and calculate their corresponding \(f(x)\) or \(f^{-1}(x)\).
  • Plot these points on a graph and connect them to form a line, since these are linear functions.
Since both functions are linear, their graphs will be straight lines. For \(f(x)\), the line will have a negative slope, moving downwards from left to right. In contrast, for \(f^{-1}(x)\), the inverse relationship often results in a graph that moves upwards. Visualizing both together on the same axes not only shows their individual patterns but also helps to check their symmetry.
Remember, to validate the inverse, the graph needs to reflect across the line \(y = x\). This line serves as a mirror, and by crossing both graphs over it, you broadly see their relationship.
Function Symmetry
Function symmetry occurs when parts of a function's graph are mirror images of each other, either over an axis or a specific line. When it comes to inverse functions like \(f(x) = 8 - 4x\) and its inverse \(f^{-1}(x) = 2 - \frac{x}{4}\), the important type of symmetry to recognize is reflective symmetry over the line \(y = x\).
  • Plotting the line \(y = x\) on the graph functions as a check for inverses.
  • The graphs of the function and its inverse should mirror each other across this line.
If they are correct inverses, each point on the graph of \(f(x)\) will correspond to a point on \(f^{-1}(x)\) in such a way that if you flip one along the line \(y = x\), they overlap. This symmetry is crucial because it confirms the mathematical inverse relationship, sealing that any input into \(f(x)\) swaps roles when processed through \(f^{-1}(x)\). Understanding this gives confidence that the inverse function has been correctly found and visualized.
Algebraic Manipulation
Algebraic manipulation is the process of rearranging and simplifying equations to find solutions or isolate variables. To solve for the inverse of \(f(x) = 8 - 4x\), we need to switch the roles of variables and isolate \(y\), using algebraic manipulation.
  • The first step involves replacing \(f(x)\) with \(y\), so \(y = 8 - 4x\).
  • Swap the variables, setting up \(x = 8 - 4y\), as you're finding the inverse.
  • Next, isolate \(y\) by performing inverse operations.
    • Add \(4y\) to both sides: \(x + 4y = 8\).
    • Move \(x\) to the other side: \(4y = 8 - x\).
    • Finally, divide each term by 4 to solve for \(y\): \(y = 2 - \frac{x}{4}\).
These steps are crucial because they transform the original function into its inverse. Understanding how to perform these manipulations is a core skill in calculus and algebra that helps solve a wide range of mathematical problems.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A capacitor is a device that stores electrical charge. The charge on a capacitor accumulates according to the function \(Q(t)=a\left(1-e^{-t / c}\right),\) where \(t\) is measured in seconds, and \(a\) and \(c>0\) are physical constants. The steady-state charge is the value that \(Q(t)\) approaches as \(t\) becomes large. a. Graph the charge function for \(t \geq 0\) using \(a=1\) and \(c=10\) Find a graphing window that shows the full range of the function. b. Vary the value of \(a\) while holding \(c\) fixed. Describe the effect on the curve. How does the steady-state charge vary with \(a ?\) c. Vary the value of \(c\) while holding \(a\) fixed. Describe the effect on the curve. How does the steady-state charge vary with \(c ?\) d. Find a formula that gives the steady-state charge in terms of \(a\) and \(c\)

A function \(y=f(x)\) such that if your car gets \(32 \mathrm{mi} /\) gal and gasoline costs \(\$ x /\) gallon, then \(\$ 100\) is the cost of taking a \(y\) -mile trip.

Factorial function The factorial function is defined for positive integers as \(n !=n(n-1)(n-2) \cdots 3 \cdot 2 \cdot 1\) a. Make a table of the factorial function, for \(n=1,2,3,4,5\) b. Graph these data points and then connect them with a smooth curve. c. What is the least value of \(n\) for which \(n !>10^{6} ?\)

The height in feet of a baseball hit straight up from the ground with an initial velocity of \(64 \mathrm{ft} / \mathrm{s}\) is given by \(h=f(t)=64 t-16 t^{2},\) where \(t\) is measured in seconds after the hit. a. Is this function one-to-one on the interval \(0 \leq t \leq 4 ?\) b. Find the inverse function that gives the time \(t\) at which the ball is at height \(h\) as the ball travels upward. Express your answer in the form \(t=f^{-1}(h)\) c. Find the inverse function that gives the time \(t\) at which the ball is at height \(h\) as the ball travels downward. Express your answer in the form \(t=f^{-1}(h)\) d. At what time is the ball at a height of \(30 \mathrm{ft}\) on the way up? e. At what time is the ball at a height of \(10 \mathrm{ft}\) on the way down?

Graphing sine and cosine functions Beginning with the graphs of \(y=\sin x\) or \(y=\cos x,\) use shifting and scaling transformations to sketch the graph of the following functions. Use a graphing utility to check your work. $$g(x)=-2 \cos (x / 3)$$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.