Oct. 2004 Facilitators Notes

Sample Tasks for Integrated Algebra, developed by New York State teachers, are clarifications, further explaining the language and intent of the associated Performance Indicators. These tasks are not test items, nor are they meant for students' use.

Note: There are no Sample Tasks for the Geometry Strand. Although there are no Performance Indicators for this strand in this section of the core curriculum, this strand is still part of instruction within the other strands as an ongoing continuum and building process of mathematical knowledge for all students.

Strands

Process

Content

Number Sense and Operations

Algebra

Geometry

Measurement

Statistics and Probability

Problem Solving Strand

A2.PS.1 Use a variety of problem solving strategies to understand new mathematical content

What connections can you make between the discriminant, the solution(s), and the graph of the function?

A2.PS.2 Recognize and understand equivalent representations of a problem situation or a mathematical concept

Given the following equations, determine the amplitude, period, frequency, and phase shift of each equation.

Two students, Anthony and Chris, can be overheard discussing these equations. Anthony is certain these equations are equivalent, while Chris insists that they are different. Which student is correct? Explain your answer fully with graphs, tables, and a carefully written paragraph supporting your position.

Students will solve problems that arise in mathematics and in other contexts.

A2.PS.3 Observe and explain patterns to formulate generalizations and conjectures

Can you see a pattern? If so, what conjecture can you make about the powers of ?

On the same set of axes, use a graphing package or graphics calculator to graph the following functions:

Sketch one cycle of each of the following equations. Carefully label each graph.

Carefully graph

and

at the same time on your calculator with a window of

. What conclusions can you make? Precisely describe the similarities between the 2 functions.

Now, carefully graph

and

at the same time on your calculator with a window of

. What conclusions can you make? Precisely describe the similarities between the 2 functions.

A2.PS.4 Use multiple representations to represent and explain problem situations (e.g., verbally, numerically, algebraically, graphically)

For each of the following values of the discriminant, state the number of x-intercepts the graph would have, and sketch a graph of a parabola that would satisfy these conditions:

Is it possible to find more than one graph with each discriminant? If so, describe how you obtained each graph and how each discriminant affects the graph.

Students will apply and adapt a variety of appropriate strategies to solve problems.

A2.PS.5 Choose an effective approach to solve a problem from a variety of strategies (numeric, graphic, algebraic)

A team of biologists have discovered a new creature in the rain forest. They note the temperature of the animal appears to vary sinusoidally over time. A maximum temperature of 125

occurs 15 minutes after they start their examination. A minimum temperature of 99

occurs 28 minutes later. The team would like to find a way to predict the animal’s temperature over time in minutes. Your task is to help them by creating a graph of one full period, an equation of temperature as a function over time in minutes, and a table of maximum, minimum, and average temperatures for the first 3 hours.

A2.PS.6 Use a variety of strategies to extend solution methods to other problems

Use the strategies learned in solving quadratic equations to solve the following equations. Express any irrational solutions in simplest radical form.

A2.PS.7 Work in collaboration with others to propose, critique, evaluate, and value alternative approaches to problem solving

With a partner, research to find three situations that can be modeled by exponential equations. Write a description of each situation and write a problem based on each of the three situations. Solve each of the problems in a different way and be prepared to present the solutions to the class.

Students will monitor and reflect on the process of mathematical problem solving.

A2.PS.8 Determine information required to solve a problem, choose methods for obtaining the information, and define parameters for acceptable solutions

Brianna decided to invest her $500 tax refund rather than spending it. She found a bank account that would pay her 4% interest compounded quarterly. If she deposits the entire $500 and does not deposit or withdraw any other amount, how long will it take her to double her money in the account?

Dante has to travel from Cambridge, NY to Buffalo, NY, a distance of approximately 333 miles. He estimates that he can average 20 mph faster during the 273 miles that he will be driving on the New York State Thruway than he can when he drives on other roads. If he wants to complete the trip in eight hours, find, to the nearest integer, the rate that Dante must travel on the Thruway.

Last year’s senior class spent $23.95 for each prom favor. This year’s prom committee knows that their prom favor must be within $5.50 of last year’s favor. Write an absolute value inequality that could be used to model the acceptable price range for this year’s prom favor, and then solve the inequality to find the range of acceptable prices for a favor. Explain you answer.

A2.PS.10 Evaluate the relative efficiency of different representations and solution methods of a problem

A bag contains three chocolate, four sugar, and five lemon cookies. Greg takes two cookies from the bag for a snack. Find the probability that Greg did not take two chocolate cookies from the bag. Explain why using the complement of the event of not choosing two chocolate cookies might be an easier approach to solving this problem.

Reasoning and Proof Strand

Students will recognize reasoning and proof as fundamental aspects of mathematics.

Read through the experiment described below. Before beginning this experiment, think about what is happening. What type of function will you expect to see? Why would you expect to see this type of function to model the data?

Based on your answer, count the number of coins that are in the cup initially and write an equation that could be used to model the number of coins remaining each time. Explain how you determined this equation. Use this equation to predict the number of times the experiment would have to be repeated until there is one coin remaining.

Take a handful of coins and put them into a cup. Shake the cup and pour the coins onto the desk.

Using the new total of coins each time, repeat the procedure until there are no coins left. When the number of coins reaches zero, the experiment is over and you should not use zero as part of your data.

Write an appropriate regression equation to model your data. What do the variables represent?

Compare this equation to the one that you wrote before the experiment began. Explain any differences between the two equations and any errors that you made in the equation that you wrote.

How many trials did it actually take until there was one coin remaining? Compare the actual number to the number predicted by the regression equation and the equation that you wrote.

A2.RP.2 Investigate and evaluate conjectures in mathematical terms, using mathematical strategies to reach a conclusion

Explain your answer using two different strategies such as a table, graph, algebraic proof, etc.

A2.RP.3 Evaluate conjectures and recognize when an estimate or approximation is more appropriate than an exact answer

Based on census data, the U.S. Census Bureau has projected the population of the United States until 2050. The table below contains these predictions.

Make a scatter plot of the data. Why do you think that the U.S. Census Bureau expressed the population in thousands?

Determine a regression equation that could be used to model the data. Use this equation to determine the number of people expected in the United States this year.

Research the current population of the United States. How does your estimate compare to the actual population? Explain why your answer is different from the actual population.

A2.RP.4 Recognize when an approximation is more appropriate than an exact answer

Trigonometric Function	Exact Value	Approximate Value

Under what circumstances would you use an approximation for each of these values, rather than giving an exact answer?

Give an example of an experiment where it is appropriate to use a normal distribution as an approximation for a binomial probability. Explain why in this example an approximation of the probability is a better approach than finding the exact probability.

A2.RP.5 Develop, verify, and explain an argument, using appropriate mathematical ideas and language

What is the range of the function

Based on your answer, what is the range of the function

Explain your answer.

A2.RP.6 Construct logical arguments that verify claims or counterexamples that refute claims

Demonstrate that

and

are inverses using at least two different strategies (numeric, graphic, algebraic).

Starting with

and using your knowledge of the quotient and reciprocal identities, derive an equivalent identity in terms of

and

. Show all your work.

Liza was absent from school and emailed two of her friends to help her understand how to decide if a relation is a function.

John said “Look at the graph. See if a vertical line crosses the graph in more than one place. If it does, then we have a function.”

Which student is correct? Why? Provide a counterexample to explain any errors made by either Mike or John.

Students will select and use various types of reasoning and methods of proof.

A2.RP.9 Support an argument by using a systematic approach to test more than one case

Sketch right triangle LMD,

Write your favorite number as the length of one of the sides. Using this information, find the lengths of the other two sides. Write the lengths as exact lengths. Do not use decimal approximations. Express the value of each of the following as the ratio of the sides of the triangle.

Reduce all of the fractions to lowest terms and compare your answers to another student’s answers. What pattern do you see? What conclusions can you reach?

Fill in another number as the length of one of the sides. Compare your answers again. Based on what you have found, determine the exact values of each of the following:

A2.RP.10 Devise ways to verify results, using counterexamples and informal indirect proof

Jenna’s teacher has asked the class to find the exact value of sin(105

). Jenna’s work is as follows.

Jenna’s teacher has marked this as incorrect. Using counterexamples or an indirect proof, demonstrate why Jenna’s work is not correct.

Let

be a point in quadrant one on the unit circle,

Draw the line segment

Let

be the angle formed by

and the positive portion of the x-axis. Now draw the perpendicular from P to meet the x-axis at point M.

Substitute your coordinates into the unit circle equation to verify one of the Pythagorean identities.

Now choose P in a different quadrant and repeat the process. Does the identity continue to be true?

Sketch a scatter plot whose regression model could be logarithmic and one whose regression model could be exponential. Use your knowledge of exponential and logarithmic functions to explain the differences and similarities in the two scatter plots.

A2.RP.12 Apply inductive reasoning in making and supporting mathematical conjectures

Given the sequence

, Paul notices a pattern and finds a formula he believes will find the sum of the first n terms. His formula is

. Show that Paul’s formula is correct.

Communication Strand

A2.CM.1 Communicate verbally and in writing a correct, complete, coherent, and clear design (outline) and explanation for the steps used in solving a problem

One of the students in class was absent the day the class learned the technique of completing the square. Using the technique of completing the square, write an explanation of how to solve the following equation that you could give to the student who had been absent:

Simplify each of the following. Assuming your friend is absent; write him a complete description on the steps necessary to simplify these problems. Include as much information as possible.

A2.CM.2 Use mathematical representations to communicate with appropriate accuracy, including numerical tables, formulas, functions, equations, charts, graphs, and diagrams

The Art Club has purchased flat sheets of cardboard to make storage boxes for the club’s art supplies. They will make boxes by cutting a square from each corner of the 24 inch by 36 inch sheet of cardboard.

Express the volume of the box as a function of the side of the square cut from the cardboard.

Make a table for the function. Use the table to find the volume of a box formed by removing a square which has a 10 inch side, and the length of the side of a square that would produce a volume of 1792 cubic inches.

Sketch a graph of the function, and use the graph to find the side of the square that would produce the maximum volume. Find the maximum volume of the box that can be made.

Make a chart containing the side of the square removed, length, width, height and volume of the box created that the club could use for quick reference to make boxes of appropriate size for the supplies. Be sure to determine an appropriate degree of accuracy for the entries in the chart.

Students will communicate their mathematical thinking coherently and clearly to peers, teachers, and others.

A2.CM.3 Present organized mathematical ideas with the use of appropriate standard notations, including the use of symbols and other representations when sharing an idea in verbal and written form

What is the domain and range of the function shown below? Express your answer in standard mathematical notation, and explain this notation.

Convert the equation

into center-radius form. When is this form of the equation more useful?

A2.CM.5 Communicate logical arguments clearly, showing why a result makes sense and why the reasoning is valid

Sally’s math teacher said you could use the conjugate of a complex number to rationalize the denominator of a fraction which contains a complex number. Sally is trying to rationalize the denominator of

but cannot remember if

is the conjugate. Which one is the conjugate and why?

A group of eight students decided that they wanted to lose weight. Four of them decided to walk a mile each school day before school. The other four of them decided to walk a mile each school day after school. All eight weigh themselves each Wednesday and report their weight to their math teacher, who is keeping it confidential.

One student in the class says this is an experiment. A second student disagrees and says this is an observational study. A third student thinks this is just a survey.

After discussing the information with your partner, write a paragraph to explain why you believe the study is an experiment, an observational study, or a survey. Be clear and concise.

A2.CM.6 Support or reject arguments or questions raised by others about the correctness of mathematical work

Two students in Ms. Baum’s class were working on a problem and got different solutions. The students each were certain they had the correct solution. Who had the correct answer? Write a detailed paragraph to explain whose work was correct and why.

It has been decided that 78 people need to be surveyed to decide the public’s opinion on a school building project. A student suggests that they survey the first 78 people who enter the school.

Do you think that this proposed way of sampling is an unbiased way to perform the survey or can you describe a better way to achieve a fair and accurate response?

Students will analyze and evaluate the mathematical thinking and strategies of others.

A2.CM.7 Read and listen for logical understanding of mathematical thinking shared by other students

Which of the following two graphs represents a function? Write an explanation of the reasoning used in obtaining this answer. Read the explanation provided by another student, and compare solutions.

Factor each of the expressions completely. Compare your answers with others in the class, discussing the process you followed to obtain the answers.

A2.CM.9 Formulate mathematical questions that elicit, extend, or challenge strategies, solutions, and/or conjectures of others

Describe a situation that would require calculating a permutation, and another situation that would require calculating a combination. Share your thoughts with a classmate and discuss the strategies used to determine when to calculate a permutation and when to calculate a combination. Write a brief summary of your conclusions and be prepared to discuss your ideas with the class.

Students will use the language of mathematics to express mathematical ideas precisely.

A2.CM.10 Use correct mathematical language in developing mathematical questions that elicit, extend, or challenge other students’ conjectures

Use the information in the table to make a conjecture about the relationship between a quadratic equation and the sum and product of its roots. Use correct mathematical language to write your conjecture.

When finished writing, exchange the paper with another student. Read the conjecture and decide whether the conjecture is valid.

If it is valid, write questions that will help the student prove that the conjecture is valid.

If the conjecture is invalid, write questions that challenge the conjecture based upon correct mathematics and mathematical reasoning.

Return the paper. Respond to the student’s questions using correct mathematical language and reasoning to prove or disprove the validity of the conjecture.

Maya has decided to train for a marathon (26 miles) and decides to set up a practice schedule to build her stamina. When she begins, she can only run 3 miles, but she intends to train every day and increase her run by 2 miles each week Find a pattern and write a formula that will give the number of miles Maya can run in week n.

Using the formula, how many weeks will Maya need to train in order to be ready for the marathon?

A2.CM.12 Understand and use appropriate language, representations, and terminology when describing objects, relationships, mathematical solutions, and rationale

Write a word problem that illustrates an application of the Law of Sines, Law of Cosines, or a combination of both. Be creative, but be certain to use appropriate language and mathematical terminology when describing the problem situation. Also prepare a complete solution of the problem including a correctly labeled diagram and full mathematical explanation of how to solve the problem.

A2.CM.13 Draw conclusions about mathematical ideas through decoding, comprehension, and interpretation of mathematical visuals, symbols, and technical writing

Define: complex number, imaginary number, real number, imaginary part, real part, conjugate

Give an example and draw a graphical representation of a complex number that fits each description:

Write the conjugate of each of the complex numbers, and draw the graphical representation of each conjugate.

How are the graphical representations of real numbers and complex numbers the same and how are they different?

How are the graphical representations of a complex number and its conjugate the same and different?

Connections Strand

A2.CN.1 Understand and make connections among multiple representations of the same mathematical idea

Describe the circle whose graph is shown below. Write an equation for the circle and name six points that lie on the circle.

In the accompanying diagram, unit circle O has radii

and

is tangent to circle O at B, and

is tangent to circle O at E. Points O, F, D, and C are collinear, and

Write an equation for a trigonometric function that matches each of the following graphs. Check your answers with a partner. If different equations have been obtained, confirm by graph or table, the accuracy of each equation.

A2.CN.2 Understand the corresponding procedures for similar problems or mathematical concepts

Solve the following inequalities graphically. Express the solutions correct to the nearest hundredth. Explain how the solutions to the two problems are related.

Students will understand how mathematical ideas interconnect and build on one another to produce a coherent whole.

A2.CN.3 Model situations mathematically, using representations to draw conclusions and formulate new situations

Stretch your arms out as wide as you can. Have someone measure across your back the length (in inches) of your arm span, from the tip of your fingers on one hand to the tip of your fingers on your other hand. Have the person also measure your height in inches. Share this information with your classmates and aggregate all of the data.

Enter the information in two lists on your calculator. In the first list, enter the heights, in inches, of all of the participants. In the second list, enter the arm span, in inches, of all of the participants.

Make a scatter plot, where the independent variable is height, in inches, and the dependent variable is arm span, in inches. What type of regression function would best model this data? Why?

A2.CN.4 Understand how concepts, procedures, and mathematical results in one area of mathematics can be used to solve problems in other areas of mathematics

Anthony’s teacher told the class that a unit circle has a circumference of

. This confused him because he thought a circle has

. Since Anthony is your friend, you would like to help him understand what the teacher means. Write a detailed explanation that compares degrees to radians. Be as thorough as possible in order to help Anthony understand the connection. Include anything that might make this clear, such as diagrams, equations, and so forth.

A2.CN.5 Understand how quantitative models connect to various physical models and representations

The angle of inclination of the sun changes throughout the year. This changing angle affects the heating and cooling of buildings. The overhang of the roof of a house is designed to shade the windows for cooling in the summer and allow the sun’s rays to enter the house for heating in the winter.

for Albany, NY, where x is the number of days elapsed in the day of the year, with January first represented by

January second represented by

and so on.

Sketch a graph illustrating the changes in the sun’s angle of inclination throughout the year.

On what date of the year is the angle of inclination at noon the greatest in Albany, NY?

Mrs. Frost has 1000 bushels of corn to sell. Presently the market price for corn is

a bushel. She expects the market price to increase by

per week. For each week she waits to sell, she loses ten bushels due to spoilage.

Determine a function to express Mrs. Frost’s total income from selling the corn. What is a reasonable domain and range for this function?

Graph the function and determine when Mrs. Frost should sell the corn to maximize her income. Show your answer is correct by computing the income one week earlier and one week later and showing these values would result in less income.

Students will recognize and apply mathematics in contexts outside of mathematics.

With a partner, research to find three situations that can be modeled by exponential equations. Write a description of each situation, write and solve one problem based on each of the three situations, and prepare to present the solution to the problem.

You just decided to save money each week in order to buy an expensive cell phone. You decide to start by saving $15 from your paycheck and then save $22 the second week and $29 the third week. You continue this pattern until you have saved enough money.

If the cell phone you want to purchase costs $585, how many weeks will you need to save enough money?

Madison was determined to help clean her local park. She collected one bag of trash the first week, 2 bags the second week, 3 bags the third week, and so on.

Assuming she continues this process, how many bags of trash will she collect in 26 weeks?

A2.CN.7 Recognize and apply mathematical ideas to problem situations that develop outside of mathematics

Use two thermometers, one Celsius and the other Fahrenheit, to measure the temperature of your hand. Place both thermometers in the palm of your hand and gently squeeze your hand shut. (If you have a temperature probe for your calculator or computer, it may be used instead.)

Enter the information in two lists on your calculator. In the first list, enter the Celsius temperatures. In the second list, enter the Fahrenheit temperatures.

Make a scatter plot, where the independent variable is degrees Celsius, and the dependent variable is degrees Fahrenheit.

What is the correlation coefficient? Why would you expect its value to be close to one?

Determine whether each of the following situations would require calculating a permutation or a combination. Explain your answer.

Selecting three students to represent the school at an Honor Society conference in Washington, D.C.

2A.CN.8 Develop an appreciation for the historical development of mathematics

Research to find out how calculations with logarithms were done before the invention of calculators.

Representation Strand

Students will create and use representations to organize, record, and communicate mathematical ideas.

A2R.1 Use physical objects, diagrams, charts, tables, graphs, symbols, equations, or objects created using technology as representations of mathematical concepts

Take a cup of very hot water, and measure the temperature of the water. Place the cup in a safe place, and measure the temperature every five seconds for a total of one minute. Record this information in your notebook.

Enter the information in two lists on your calculator. In the first list, enter the time, in seconds, since the experiment began. In the second list, enter the temperature of the water for each indicated time.

Make a scatter plot, where the independent variable is time, in seconds, and the dependent variable is temperature. What type of regression function would best model this data? Why?

Write the regression equation with all constants rounded to the nearest thousandth.

Using this equation, determine the temperature of the water after 25 seconds has passed. Determine the temperature of the water after two hours has passed. Do both of these answers seem logical to you? Why?

(N.B. If you have a temperature probe for your calculator or computer, it may be used to conduct this experiment.)

Explain clearly in words and with a pair of graphs, the differences between the function

and each of the following functions.

After examining the four sets of graphs, graph one sine function containing all four transformations. Write the equation of the new graph.

How do the coordinates of the center of a circle relate to C and D when the equation of the circle is in the form ?

A2.R.3 Use representation as a tool for exploring and understanding mathematical ideas

Use the technique of completing the square to write the equation

in an appropriate form to find the transformations that produce the graph of the given equation from the graph of the equation

Students will select, apply, and translate among mathematical representations to solve problems.

Carlos drove from his home to Union College in 4 hours at 55 mph. How long would it take him if he had traveled at 65 mph?

Keisha earned $44.70 for working 6 hours. How much does she earn for working 8.5 hours?

A2.R.5 Investigate relationships between different representations and their impact on a given problem

A company offers its employees a choice of two salary schemes (A and B) over a period of ten years. Scheme A offers a starting salary of $33,000 in the first year and an annual increase of $1200 per year. Scheme B offers a starting salary of $30,000 in the first year and an annual increase of 7% of the previous year’s salary. An employee about to join this company hires you to examine the two schemes. Decide which scheme is better financially for the employee. Prepare a variety of ways to present the information to the client, such as tables and graphs.

Students will use representations to model and interpret physical, social, and mathematical phenomena.

A2.R.6 Use mathematics to show and understand physical phenomena (e.g., find the height of a building if a ladder of a given length forms a given angle of elevation with the ground)

The table shows the amount of medicine for treating a disease in the bloodstream over the 9 hours following a dose of 10 mg. It seems that the rate of decrease of medicine is approximately proportional to the amount remaining.

Using your model, when will there be less than 1 mg. of medicine in the patient’s blood stream?

If the initial dose was 15 mg, when would the amount of medicine in the bloodstream, fall below 5 mg?

According to the National Weather Service, the 2005 average monthly temperature, in degrees Fahrenheit, at Central Park in New York City is given below:

Write a sinusoidal function that models the average monthly temperature, using t = 1 to represent January. According to your model, what is the average temperature in December? Explain the discrepancy from your model to the average monthly temperature in December. How could the model be improved?

A2.R.7 Use mathematics to show and understand social phenomena (e.g., interpret the results of an opinion poll)

Search in newspapers and magazines and then write a brief but thorough description of a study that could be characterized as:

A2.R.8 Use mathematics to show and understand mathematical phenomena (e.g., use random number generator to simulate a coin toss)

Use a random number generator to generate thirty random numbers that will simulate tossing a fair coin thirty times. Let an even number represent the result of the coin coming up heads, and an odd number represent the result of tails. Generate a second list of thirty random numbers to represent the second toss of a fair coin. Use the two lists of random numbers to compute the following empirical probabilities: P(head, tail), P(both the same), P(both different). Compute the following theoretical probabilities for the same experiment: P(head, tail), P(both the same), P(both different). How do the empirical and theoretical probabilities compare?

Number Sense and Operations

Students will understand meanings of operations and procedures, and how they relate to one another.

A2.N.1 Evaluate numerical expressions with negative and/or fractional exponents, without the aid of a calculator (when the answers are rational numbers)

A2.N.2 Perform arithmetic operations (addition, subtraction, multiplication, division) with expressions containing irrational numbers in radical form

A2.N.3 Perform arithmetic operations with polynomial expressions containing rational coefficients

Simplify the problems below. Your friend was absent. Write your friend a complete description of the steps necessary to simplify the problems.

Can you see a pattern? If so, what conjecture can you make about the powers of ?

but cannot remember if

is the conjugate. Which one is the conjugate and why?

Research and define: complex number, imaginary number, real number, imaginary part, real part, conjugate

Give an example and draw a graphical representation of a complex number that fits each description:

Write the conjugate of each of the complex numbers, and draw the graphical representation of each conjugate.

How are the graphical representations of real numbers and complex numbers the same and how are they different?

How are the graphical representations of a complex number and its conjugate the same and different?

A2.N.9 Perform arithmetic operations on complex numbers and write the answer in the form Note: This includes simplifying expressions with complex denominators.

Adrianna decided to save money each week in order to buy an expensive sound system. She decide to start by saving $15 from her first paycheck, and then save $22 the second week and $29 the third week. She continued this pattern until she had saved enough money.

If the sound system she wanted to purchase costs $585, how many weeks will she need to save enough money?

Algebra

Students will represent and analyze algebraically a wide variety of problem solving situations.

A2.A.1 Solve absolute value equations and inequalities involving linear expressions in one variable

Last year’s senior class spent $23.95 for each yearbook. This year’s yearbook committee knows that their yearbook must be within $5.50 of last year’s favor. Write an absolute value inequality that could be used to model the acceptable price range for this year’s yearbook, and then solve the inequality to find the range of acceptable prices for the yearbook.

A2.A.2 Use the discriminant to determine the nature of the roots of a quadratic equation

Describe the nature of the roots of the quadratic equation whose discriminant is:

What connections can you make between the discriminant, the solution(s), and the graph of the function?

A2.A.3 Solve systems of equations involving one linear equation and one quadratic equation algebraically Note: This includes rational equations that result in linear equations with extraneous roots.

A2.A.4 Solve quadratic inequalities in one and two variables, algebraically and graphically

Solve the following inequalities algebraically, and then check the solutions graphically:

Solve the following inequalities graphically. Express the solutions rounded to the nearest hundredth. Explain how the solutions to the two problems are related.

1.) Carlos drove from his home to Union College in 4 hours at 55 mph. How long would it have taken him if he had traveled at 65 mph?

2.) Keisha earned $44.70 for working 6 hours. How much will she earn for working 8 hours?

Brianna decided to invest her $500 tax refund rather than spending it. She found a bank that would pay her 4% interest, compounded quarterly. If she deposits the entire $500 and does not deposit or withdraw any other amount, how long will it take her to double her money in the account?

A2.A.7 Factor polynomial expressions completely, using any combination of the following techniques: common factor extraction, difference of two perfect squares, quadratic trinomials

Factor each of the expressions completely. Discuss the process that you followed to obtain the answers.

A2.A.8 Apply the rules of exponents to simplify expressions involving negative and/or fractional exponents

A2.A.9 Rewrite algebraic expressions that contain negative exponents using only positive exponents

Rewrite each of the following expressions, using only positive exponents, with none of the variables equal to zero:

A2.A.10 Rewrite algebraic expressions with fractional exponents as radical expressions

Rewrite the three expressions below, using radicals. All of the variables are positive numbers.

A2.A.11 Rewrite algebraic expressions in radical form as expressions with fractional exponents

Rewrite the radical expressions below, using exponents. All of the variables are positive numbers.

A2.A.14 Perform addition, subtraction, multiplication, and division of radical expressions

A2.A.16 Perform arithmetic operations with rational expressions and rename to lowest terms

A2.A.19 Apply the properties of logarithms to rewrite logarithmic expressions in equivalent forms

Explain your answer using two different strategies ( e.g., use a table, a graph, an algebraic proof, etc.).

A2.A.20 Determine the sum and product of the roots of a quadratic equation by examining its coefficients

Find the sum of the roots and the product of the roots for the following quadratic equations:

A2.A.21 Determine the quadratic equation, given the sum and product of its roots

Write a quadratic equation whose roots have a sum of 4 and a product of -4, and find the roots of this equation.

If a quadratic equation has the roots given below, find the sum of the roots, find the product of the roots, and write a quadratic equation with the given roots.

When finished writing, exchange the paper with another student. Read the conjecture and decide whether the conjecture is valid.

If it is valid, write questions that will help the student prove that the conjecture is valid.

If the conjecture is invalid, write questions that challenge the conjecture based upon correct mathematics and mathematical reasoning.

Return the paper. Respond to the student’s questions using correct mathematical language and reasoning to prove or disprove the validity of the conjecture.

Explain how to determine the number of solutions to a radical equation without actually solving an equation.

Dante has to travel from Cambridge, New York to Buffalo, New York, a distance of approximately 333 miles. He estimates that he can average 20 mph faster during the 273 miles that he will be driving on a main highway than he can when he drives on back roads. If he wants to complete the trip in eight hours, find, to the nearest integer, the rate that Dante must travel on the main highway.

One of the students in class was absent the day the class learned the technique of completing the square. Write an explanation of how to solve the following equation using the technique of completing the square that you could give to the student who had been absent:

Use the technique of completing the square to write the equation

in an appropriate form to find the transformations that produce the graph of the given equation from the graph of the equation

A2.A.26 Find the solution to polynomial equations of higher degree that can be solved using factoring and/or the quadratic formula

Solve the following equations. Express any irrational solutions in simplest radical form.

Solve the following equations. Express solutions correct to the nearest hundredth.

A2.A.28 Solve a logarithmic equation by rewriting as an exponential equation

Students will recognize, use, and represent algebraically patterns, relations, and functions.

A2.A.29 Identify an arithmetic or geometric sequence and find the formula for its nth term

Maya has decided to train for a marathon (26 miles) and has set up a practice schedule to build her stamina. When she began she was able to run 3 miles, but she intends to train every day and increase her run by 2 miles each week. Find a pattern and write a formula that will give the number of miles Maya can run in week n.

Using the formula, how many weeks will Maya need to train in order to be ready for the marathon?

Dahar is taking a class in word processing and is trying to increase his typing speed. When he began, he could type 20 words per minute. He practiced faithfully every day and noticed an increase in his speed of 10% per week. Find a pattern and write a formula that will give the number of words per minute Dahar can type in n weeks.

Using the formula, how many weeks will Dahar need to practice in order to type 60 words per minute?

What is the common difference in the arithmetic sequence defined by the following formula?

What is the common ratio in the geometric sequence defined by the following formula?

A2.A.35 Determine the sum of the first n terms of an arithmetic or geometric series

Madison was determined to help clean her local park. She collected one bag of trash the first week, 2 bags the second week, 3 bags the third week, and continued at the same rate.

Assuming she continues this process, how many bags of trash will she collect in 26 weeks?

If Madison collected one bag of trash the first week, 2 bags the second week, 4 bags the third week, and continued at the same rate, how many bags of trash would she collect in 26 weeks?

Given the sequence

, Paul notices a pattern and finds a formula he believes will find the sum of the first n terms. His formula is

. Show that Paul’s formula is correct.

A2.A.36 Apply the binomial theorem to expand a binomial and determine a specific term of a binomial expansion

Use the definition of a relation to explain why the set {(-3,5), (4,7), (4,5)} is a relation.

Use the definition of a function to explain why the set {(-3,5), (4,7), (0,5)} is a function.

Liza was absent from school and emailed two of her friends to help her understand how to decide if a relation is a function.

John said: Look at the graph. See if a vertical line crosses the graph in more than one place. If it does, then we have a function.

Which student is correct? Why? Provide a counterexample to explain any errors made by either Mike or John.

Mrs. Frost has 1000 bushels of corn to sell. Presently the market price for corn is

a bushel. She expects the market price to increase by

per week. For each week she waits to sell, she loses ten bushels due to spoilage.

Determine a function to express Mrs. Frost’s total income from selling the corn. What is a reasonable domain and range for this function?

A2.A.41 Use functional notation to evaluate functions for given values in the domain

John claims that he performs the composition of functions each morning when he puts on his shoes and socks. Is he correct? Explain.

For each of the following functions, state whether the function is one-to-one, onto, neither, or both:

Use the definition of the inverse of a function to explain why

is the inverse of the function

A2.A.45 Determine the inverse of a function and use composition to justify the result

Find the inverse of the following functions. Use composition to show your result is the inverse of the given function.

Demonstrate that

and

are inverses using at least two different strategies (numeric, graphic or algebraic).

On the same set of axes, graph

and

. What transformation describes the relationship between

and

? What transformation describes the relationship between

and

? Use the answers to these questions to predict what the graph of

and

will look like, then use a graphing calculator to check your prediction. Write a description of how the graph of

and the graph of

are related.

Write an equation for the graph of the function,

obtained by shifting the graph of

three units to the left, stretching the graph vertically by a factor of two, reflecting that result over the x – axis, and then translating the graph up four units.

Describe the transformations that would produce the graph of the second function from the graph of the first function:

Explain clearly in words and with a pair of graphs, the differences between the function

and each of the following functions.

After examining the four sets of graphs, graph one sine function containing all four transformations. Write the equation of the new graph.

A2.A.47 Determine the center-radius form for the equation of a circle in standard form

Use the technique of completing the square to convert the equation

into center-radius form. What is the center and what is the radius of this equation?

Convert the equation

into center-radius form. When is this form of the equation more useful?

Quadratic Equation	Roots	Sum of Roots	Product of Roots

Time(hours)	0	1	2	3	4	5	6	7	8
Drug Amount (mg)	10	8.3	7.2	6.0	5.0	4.4	3.7	2.8	2.5

Quadratic Equation	Roots	Sum of Roots	Product of Roots