/*! 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 6 Find the relative extrema of eac... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the relative extrema of each function, if they exist. List each extremum along with the \(x\) -value at which it occurs. Then sketch a graph of the function. $$F(x)=0.5 x^{2}+2 x-11$$

Short Answer

Expert verified
The relative minimum is at \((x, y) = (-2, -13)\).

Step by step solution

01

- Find the First Derivative

First, find the first derivative of the function. The first derivative will help identify critical points. Given:\[F(x) = 0.5x^2 + 2x - 11\]The first derivative is:\[F'(x) = d/dx (0.5x^2 + 2x - 11)\]\[F'(x) = 0.5 \times 2x + 2 = x + 2\]
02

- Find Critical Points

Set the first derivative equal to zero to find the critical points:\[F'(x) = x + 2 = 0\]Solve for \(x\):\[x = -2\]
03

- Determine the Nature of Critical Points

Use the second derivative test to determine if the critical point is a maximum, minimum, or neither. The second derivative is:\[F''(x) = d/dx (x + 2) = 1\]Since \(F''(x) > 0\), the critical point at \(x = -2\) is a relative minimum.
04

- Find the Function Value at the Critical Point

Substitute \(x = -2\) back into the original function to find the \(y\)-value:\[F(-2) = 0.5(-2)^2 + 2(-2) - 11\]\[F(-2) = 0.5(4) - 4 - 11\]\[F(-2) = 2 - 4 - 11 = -13\]So the relative minimum occurs at \((x, y) = (-2, -13)\).
05

- Sketch the Graph

To sketch the graph, plot the parabolic function \(F(x) = 0.5x^2 + 2x - 11\) and clearly mark the relative minimum at \( (-2, -13) \). Since the coefficient of \(x^2\) is positive, the parabola opens upwards.

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.

Critical Points
Critical points are key to understanding the behavior of a function. They occur where the first derivative of the function is zero or undefined. When the derivative is zero, it means the slope of the tangent line is flat at that point. In our example, we found the first derivative:
\[F'(x) = x + 2\]
Setting the first derivative equal to zero and solving for \(x\) gives us the critical point:
\[x + 2 = 0 \rightarrow x = -2\]
This indicates that \(x = -2\) is a critical point. Checking whether this point is a maximum, minimum, or neither requires further analysis, often involving additional tests like the second derivative test.
First Derivative
The first derivative of a function gives us the rate of change or slope of the function's graph. It is crucial for finding critical points and understanding the behavior of the function. In this example, the function is:
\[F(x) = 0.5x^2 + 2x - 11\]
Taking the first derivative, we get:
\[F'(x) = d/dx (0.5x^2 + 2x - 11) = x + 2\]
This tells us how the function changes at different points. Setting the first derivative to zero helps identify points where the function might have a relative extremum.
Second Derivative Test
The second derivative test helps determine the nature of a critical point (whether it's a maximum, minimum, or neither). We obtain the second derivative by differentiating the first derivative. For our function, the second derivative is:
\[F''(x) = d/dx(x + 2) = 1\]
In this test:
  • If \(F''(x) > 0\), the critical point is a relative minimum.
  • If \(F''(x) < 0\), the critical point is a relative maximum.
  • If \(F''(x) = 0\), the test is inconclusive.
In our example, since \(F''(x) = 1 > 0\), the critical point at \(x = -2\) is identified as a relative minimum.
This information helps us understand how the function behaves around that point.
Parabolic Graph
A parabolic graph represents a quadratic function and has a signature 'U' shape if the leading coefficient is positive and an 'n' shape if it's negative. For the function \(F(x) = 0.5x^2 + 2x - 11\), since the coefficient of \(x^2\) is positive (0.5), the parabola opens upwards.
Here's what you need to sketch it:
  • Identify the vertex: For our function, the vertex is found at the critical point \((-2, -13)\).
  • Determine the direction: The positive coefficient confirms the parabola opens upwards.
  • Plot additional points if necessary: This improves the accuracy of the graph.
With this understanding, you can sketch the graph, marking the relative minimum at \((-2, -13)\). This point is the lowest on the graph, making it the vertex of the upward-opening parabola.

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

Assume the function \(f\) is differentiable over the interval \((-\infty, \infty)\) : that is, it is smooth and continuous for all real numbers \(x\) and has no corners or vertical tangents. Classify each of the following statements as cither true or false. If you choose false, explain why. The function \(f\) can have no extrema but can have at least one point of inflection.

It is known that homing pigeons tend to avoid flying over water in the daytime, perhaps because the downdrafts of air over water make flying difficult. Suppose that a homing pigeon is released on an island at point \(C,\) which is \(3 \mathrm{mi}\) directly out in the water from a point \(B\) on shore. Point \(B\) is 8 mi downshore from the pigeon's home loft at point \(A\). Assume that a pigeon flying over water uses energy at a rate 1.28 times the rate over land. Toward what point \(S\) downshore from \(A\) should the pigeon fly in order to minimize the total energy required to get to the home loft at \(A\) ? Assume that Total energy \(=\) (Energy rate over water) \(\cdot\) (Distance over water) \(+\) (Energy rate over land) \(\cdot\) (Distance over land).

Not all asymptotes are linear. Use long division to find an equation for the nonlinear asymptote that is approached by the graph of $$f(x)=\frac{x^{5}+x-9}{x^{3}+6 x}$$ Then graph the function and its asymptote.

Use your calculator's absolute-value feature to graph the follow. ing functions and determine relative extrema and intervals over which the function is increasing or decreasing. State the \(x\) -values at which the derivative does not exist. $$f(x)=|x-2|$$

Total revenue, cost, and profit. Using the same set of axes. sketch the graphs of the total-revenue, total-cost, and total. profit functions. Small business. The percentage of the U.S. national income generated by nonfarm proprietors may be modeled by the function $$ p(x)=\frac{13 x^{3}-240 x^{2}-2460 x+585,000}{75,000} $$ where \(x\) is the number of years since \(1970 .\) Sketch the graph of this function for \(0 \leq x \leq 40\)

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.