/*! 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 4 The number of species of a given... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

The number of species of a given taxonomic group within a given habitat (often an island) is a function of the area of the habitat. For islands in the West Indies, the formula $$ S(A)=3 A^{0.3} $$ approximates the number \(S\) of species of amphibians and reptiles on an island in terms of the island area \(A\) in square miles. This is an example of a species-area relation. a. Make a table giving the value of \(S\) for islands ranging in area from 4000 to 40,000 square miles. b. Explain in practical terms what \(S(4000)\) means and calculate that value. c. Use functional notation to express the number of species on an island whose area is 8000 square miles, and then calculate that value. d. Would you expect a graph of \(S\) to be concave up or concave down?

Short Answer

Expert verified
S(4000) is about 61 species; S(8000) is about 83 species; the graph is concave down.

Step by step solution

01

Calculating S for a Range of Areas

To make a table of values for islands with areas ranging from 4000 to 40,000 square miles, calculate \(S(A)\) for several values. You can choose intervals like every 4000 square miles. For each area \(A\), use the formula \(S(A) = 3A^{0.3}\). For example, for \(A = 4000\), we compute \(S(4000) = 3(4000)^{0.3}\), and repeat for other values like 8000, 12000, etc.| Area \(A\) (sq miles) | Number of Species \(S(A)\) ||-------------------|-------------------------|| 4000 | 60.74 || 8000 | 83.30 || 12000 | 100.31 || 16000 | 114.61 || 20000 | 126.93 || 24000 | 137.78 || 28000 | 147.47 || 32000 | 156.17 || 36000 | 164.03 || 40000 | 171.14 |
02

Interpreting S(4000)

The expression \(S(4000)\) represents the estimated number of species of amphibians and reptiles on an island that has an area of 4000 square miles. Using the formula, calculate it: \(S(4000) = 3(4000)^{0.3} \approx 60.74\). This means there are approximately 61 species on such an island.
03

Express and Calculate S(8000)

To find the number of species on an island of 8000 square miles using functional notation, express it as \(S(8000)\). Calculate the value: \(S(8000) = 3(8000)^{0.3} \approx 83.30\). This implies the island has about 83 species.
04

Analyzing Graph Concavity of S

To determine whether \(S(A)\) is concave up or down, consider the second derivative \(S''(A)\). Since \(S(A) = 3A^{0.3}\), the first derivative \(S'(A)\) is \(0.9A^{-0.7}\), and the second derivative \(S''(A)\) is \(-0.63A^{-1.7}\). Because \(S''(A) < 0\) for all \(A > 0\), the graph of \(S(A)\) is concave down.

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.

Mathematical Modeling
Mathematical modeling is a crucial tool in understanding complex real-world phenomena by creating a mathematical representation. In the case of the species-area relationship, we use the formula \( S(A) = 3A^{0.3} \) to predict how the number of species of amphibians and reptiles varies with the size of an island. This model expresses a quantitative link between a habitat's area \( A \) and the expected biodiversity \( S \).

Mathematical models are pivotal for making predictions and planning conservation strategies. They help in assessing how changes in habitat size might affect species diversity. By using mathematical models, scientists can also test hypotheses and gain insights into environmental dynamics.

In this exercise, the model is rather straightforward and captures an essence of reality in a simple form. The model’s power lies in its simplicity and ability to provide approximate values without needing direct observation or exhaustive surveys.
Exponential Growth
Exponential growth is a pattern of data that steadily escalates over time, or increases at a constant rate per unit interval. While the formula \( S(A) = 3A^{0.3} \) in this exercise isn't a pure exponential equation, it exhibits growth as the area increases. Specifically, it shows how the number of species increases at a decreasing rate as the island size grows larger.

This kind of growth is not arbitrary but reflects biological limits—larger areas accommodate more species, but each successive unit of area contributes less to the number of additional species. This is crucial for understanding resource allocation and environmental impacts since it implies diminishing returns on larger habitat expansions.

Understanding exponential growth, even in this adapted form, is essential for areas like ecology and environmental science, as it highlights both opportunities for biodiversity and potential constraints.
Graph Interpretation
Graph interpretation is a key skill in data analysis, facilitating comprehension of patterns, trends, and behaviors shown in visual forms. In this exercise, interpreting the graph of \( S(A) = 3A^{0.3} \) involves recognizing its concave down shape, which the analysis of the second derivative confirmed with \( S''(A) < 0 \).

When a graph is concave down, it implies that while the function is increasing, the rate of increase is slowing down. As the island's area becomes larger, the increase in species count begins to taper off. This fits with the species-area relationship that larger areas will house more species, but the increase is subject to natural limits.

Effectively understanding graphs means recognizing these subtleties. Graphs offer a powerful way to visualize mathematical relationships, making complex data more accessible to interpret and rely upon for decision-making.

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 mole of a chemical compound is a fixed number, \({ }^{16}\) like a dozen, of molecules (or atoms in the case of an element) of that compound. A mole of water, for example, is about 18 grams, or just over a half an ounce in your kitchen. Chemists often use the mole as the measure of the amount of a chemical compound. A mole of carbon dioxide has a fixed mass, but the volume \(V\) that it occupies depends on pressure \(p\) and temperature \(T\); greater pressure tends to compress the gas into a smaller volume, whereas increasing temperature tends to make the gas expand into a larger volume. If we measure the pressure in atmospheres ( 1 atm is the pressure exerted by the atmosphere at sea level), the temperature in kelvins, and the volume in liters, then the relationship is given by the ideal gas law: $$ p V=0.082 T \text {. } $$ a. Solve the ideal gas law for the volume \(V\). b. What is the volume of 1 mole of carbon dioxide under \(3 \mathrm{~atm}\) of pressure at a temperature of 300 kelvins? c. Solve the ideal gas law for pressure. d. What is the pressure on 1 mole of carbon dioxide if it occupies a volume of \(0.4\) liter at a temperature of 350 kelvins? e. Solve the ideal gas law for temperature. f. At what temperature will 1 mole of carbon dioxide occupy a volume of 2 liters under a pressure of \(0.3 \mathrm{~atm}\) ?

The economic order quantity model tells a company how many items at a time to order so that inventory costs will be minimized. The number \(Q=Q(N, c, h)\) of items that should be included in a single order depends on the demand \(N\) per year for the product, the fixed cost \(c\) in dollars associated with placing a single order (not the price of the item), and the carrying cost \(h\) in dollars. (This is the cost of keeping an unsold item in stock.) The relationship is given by $$ Q=\sqrt{\frac{2 N c}{h}} $$ a. Assume that the demand for a certain item is 400 units per year and that the carrying cost is \(\$ 24\) per unit per year. That is, \(N=400\) and \(h=24\). i. Find a formula for \(Q\) as a function of the fixed ordering \(\operatorname{cost} c\), and plot its graph. For this particular item, we do not expect the fixed ordering costs ever to exceed \(\$ 25\). ii. Use the graph to find the number of items to order at a time if the fixed ordering cost is \$6 per order. iii. How should increasing fixed ordering cost affect the number of items you order at a time? b. Assume that the demand for a certain item is 400 units per year and that the fixed ordering cost is \(\$ 14\) per order. i. Find a formula for \(Q\) as a function of the carrying cost \(h\) and make its graph. We do not expect the carrying cost for this particular item ever to exceed \(\$ 25\). ii. Use the graph to find the optimal order size if the carrying cost is \(\$ 15\) per unit per year. iii. How should an increase in carrying cost affect the optimal order size? iv. What is the average rate of change per dollar in optimal order size if the carrying cost increases from \(\$ 15\) to \(\$ 18 ?\) v. Is this graph concave up or concave down? Explain what that tells you about how optimal order size depends on carrying costs.

The monthly profit \(P\) for a widget producer is a function of the number \(n\) of widgets sold. The formula is $$ P=-15+10 n-0.2 n^{2} . $$ Here \(P\) is measured in thousands of dollars, \(n\) is measured in thousands of widgets, and the formula is valid up to a level of 15 thousand widgets sold. a. Make a graph of \(P\) versus \(n\). b. Calculate \(P(1)\) and explain in practical terms what your answer means. c. Is the graph concave up or concave down? Explain in practical terms what this means. d. The break-even point is the sales level at which the profit is 0 . Find the break-even point for this widget producer.

A child has 64 blocks that are 1 -inch cubes. She wants to arrange the blocks into a solid rectangle \(h\) blocks long and \(w\) blocks wide. There is a relationship between \(h\) and \(w\) that is determined by the restriction that all 64 blocks must go into the rectangle. A rectangle \(h\) blocks long and \(w\) blocks wide uses a total of \(h \times w\) blocks. Thus \(h w=64\). Applying some elementary algebra, we get the relationship we need: $$ w=\frac{64}{h} . $$ a. Use a formula to express the perimeter \(P\) in terms of \(h\) and \(w\). b. Using Equation (2.3), find a formula that expresses the perimeter \(P\) in terms of the height only. c. How should the child arrange the blocks if she wants the perimeter to be the smallest possible? d. Do parts \(b\) and \(c\) again, this time assuming that the child has 60 blocks rather than 64 blocks. In this situation the relationship between \(h\) and \(w\) is \(w=60 / h\). (Note: Be careful when you do part c. The child will not cut the blocks into pieces!)

The growth \(G\) of a population over a week is a function of the population size \(n\) at the beginning of the week. If both \(n\) and \(G\) are measured in thousands of animals, the formula is $$ G=-0.25 n^{2}+5 n \text {. } $$ a. Make a graph of \(G\) versus \(n\). Include values of \(n\) up to 25 thousand animals. b. Use functional notation to express the growth over a week if the population at the beginning is 4 thousand animals, and then calculate that value. c. Calculate \(G(22)\) and explain in practical terms what your answer means. d. For what values of \(n\) is the function \(G\) increasing? Determine whether the graph is concave up or concave down for these values, and explain in practical terms what this means.

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.