Orientation Assignment2

course Phy202

ss|y[ܡⷃ{yassignment #001

001. Only assignment: prelim asst

qa prelim

......!!!!!!!!...................................

10:42:46

`q001. Part 1 includes six activities. If you have completed an activity, just enter the answer 'completed'.

This question is appearing in the Question box. The box to the right is the Answer box, where you will type in your answers to the questions posed here.

To use this program you read a question, then enter your answer in the Answer box and click on Enter Answer. In your answers give what is requested, but don't go into excruciating detail. Try to give just enough that the instructor can tell that you understand an item.

After entering an answer click on Next Question/Answer above the Question box.

Do you understand these instructions?

......!!!!!!!!...................................

RESPONSE -->

yes

.................................................

......!!!!!!!!...................................

10:46:08

This program has created the folder c:\vhmthphy on your hard drive.

Browse to that folder and locate the file whose name begins with SEND. The name of this file will also include your name, as you gave it to the program, and the file will show as a Text file.

Never tamper with a SEND file in any way. It contains internal codes as if these codes are tampered with you won't get credit for the assignment. However you are welcome to copy this file to another location and view it, make changes, etc. Just be sure that when requested to do so you send the instructor the original, tamper-free file.

State in the Answer box whether or not you have been able to locate the SEND file. Don't send the SEND file yet. Note that more questions/instructions remain in the q_a_prelim.

......!!!!!!!!...................................

RESPONSE -->

I have located the file ""send"", I also have a ""master file"" under this folder

.................................................

......!!!!!!!!...................................

10:48:12

`q002. Note that every time you click on Enter Answer the program writes your response to your SEND file. Even if the program disappears all the information you have entered with the Enter Answer button will remain in that file. This program never 'unwrites' anything. Even if this program crashes your information will still be there in the SEND file. Explain this in your own words.

......!!!!!!!!...................................

RESPONSE -->

The ""send"" file is storing my answers (and also the questions) that appear in the next question box. Once I enter the info, it stays in the send file, even if this program is lost or glitches.

.................................................

......!!!!!!!!...................................

10:49:29

Any time the instructor does not post a response to your access site by the end of the following day, you should resubmit your work using the Submit Work form, and be sure at the beginning to indicate that you are resubmitting, and also indicate the date on which you originally submitted your work.

If you don't know where your access site is or how to access it, go to

http://www.vhcc.edu/dsmith/_vti_bin/shtml.dll/request_access_code.htm and request one now. You can submit the q_a_prelim without your access code, but other assignments should contain your code.

......!!!!!!!!...................................

RESPONSE -->

I have requested access code.

.................................................

......!!!!!!!!...................................

10:50:49

`q003. If you are working on a VHCC computer, it is probably set up in such a way as to return to its original configuration when it is rebooted. To avoid losing information it is suggested that you back up your work frequently, either by emailing yourself a copy or by using a key drive or other device. This is a good idea on any computer. Please indicate your understanding of this suggestion.

......!!!!!!!!...................................

RESPONSE -->

I understand that it is suggested that my work should be saved on some type of memory device or by email.

.................................................

......!!!!!!!!...................................

10:53:03

Once more, locate the SEND file in your c:\vhmthphy folder, and open the file. Copy its contents to the clipboard (this is a common operation, but in case you don't know how, just use CTRL-A to highlight the contents of the file and CTRL-C to copy the contents to the clipboard). Then return to the form that instructed you to run this program, and paste the contents into the indicated box (just right-click in the box and select Paste).

You may now click on the Quit button, or simply close the program.

......!!!!!!!!...................................

RESPONSE -->

ss|y[ܡⷃ{y

assignment #001

001. Only assignment: prelim asst

qa prelim

......!!!!!!!!...................................

10:42:46

`q001. Part 1 includes six activities. If you have completed an activity, just enter the answer 'completed'.

This question is appearing in the Question box. The box to the right is the Answer box, where you will type in your answers to the questions posed here.

To use this program you read a question, then enter your answer in the Answer box and click on Enter Answer. In your answers give what is requested, but don't go into excruciating detail. Try to give just enough that the instructor can tell that you understand an item.

After entering an answer click on Next Question/Answer above the Question box.

Do you understand these instructions?

......!!!!!!!!...................................

RESPONSE -->

yes

.................................................

......!!!!!!!!...................................

10:46:08

This program has created the folder c:\vhmthphy on your hard drive.

Browse to that folder and locate the file whose name begins with SEND. The name of this file will also include your name, as you gave it to the program, and the file will show as a Text file.

Never tamper with a SEND file in any way. It contains internal codes as if these codes are tampered with you won't get credit for the assignment. However you are welcome to copy this file to another location and view it, make changes, etc. Just be sure that when requested to do so you send the instructor the original, tamper-free file.

State in the Answer box whether or not you have been able to locate the SEND file. Don't send the SEND file yet. Note that more questions/instructions remain in the q_a_prelim.

......!!!!!!!!...................................

RESPONSE -->

I have located the file ""send"", I also have a ""master file"" under this folder

.................................................

......!!!!!!!!...................................

10:48:12

`q002. Note that every time you click on Enter Answer the program writes your response to your SEND file. Even if the program disappears all the information you have entered with the Enter Answer button will remain in that file. This program never 'unwrites' anything. Even if this program crashes your information will still be there in the SEND file. Explain this in your own words.

......!!!!!!!!...................................

RESPONSE -->

The ""send"" file is storing my answers (and also the questions) that appear in the next question box. Once I enter the info, it stays in the send file, even if this program is lost or glitches.

.................................................

......!!!!!!!!...................................

10:49:29

Any time the instructor does not post a response to your access site by the end of the following day, you should resubmit your work using the Submit Work form, and be sure at the beginning to indicate that you are resubmitting, and also indicate the date on which you originally submitted your work.

If you don't know where your access site is or how to access it, go to

http://www.vhcc.edu/dsmith/_vti_bin/shtml.dll/request_access_code.htm and request one now. You can submit the q_a_prelim without your access code, but other assignments should contain your code.

......!!!!!!!!...................................

RESPONSE -->

I have requested access code.

.................................................

......!!!!!!!!...................................

10:50:49

`q003. If you are working on a VHCC computer, it is probably set up in such a way as to return to its original configuration when it is rebooted. To avoid losing information it is suggested that you back up your work frequently, either by emailing yourself a copy or by using a key drive or other device. This is a good idea on any computer. Please indicate your understanding of this suggestion.

......!!!!!!!!...................................

RESPONSE -->

I understand that it is suggested that my work should be saved on some type of memory device or by email.

.................................................

.}ټqܣLs

assignment #001

001. Rates

qa rates

01-30-2009

......!!!!!!!!...................................

12:27:03

`q001. You should copy and paste these instructions to a word processor for reference. However you can always view them, as well as everything else that has appeared in this box, by clicking the 'Display Everything' button.

1. For the next question or answer, you click on 'Next Question / Answer' button above the box at top left until a question has been posed. Once a question has been posed you are to answer before you click again on this button.

2. Before clicking for an answer, type your best answer to the current question into the box to the right, then clip on the 'Enter Answer' button.

3. After entering your answer you will click on 'Next Question / Answer' to view the answer to the question. Do not tamper with the information displayed in the left-hand box.

4. If your answer was incorrect, incomplete or would otherwise require revision, you will enter a self-critique. If you learned something from the answer, you need to restate it in your own words in order to reinforce your learning. If there is something you feel you should note for future reference, you should make a note in your own words. Go to the response box (the right-hand box) and type in a self-critique and/or notes, as appropriate. Do not copy and paste anything from the left-hand box, since that information will be saved in any case.

5. If you wish to save your response to your Notes file you may choose to click on the 'Save As Notes' button rather than the 'Enter Answer' button. Doing so will save your work for your future reference. Your work will be saved in a Notes file in the c:\vhmthphy folder. The title of the Notes file will also include the name you gave when you started the program.

6. After clicking either the 'Enter Response' or the 'Save as Notes' button, click on 'Next Question / Answer' and proceed in a similar manner.

In the right-hand box briefly describe your understanding of these instructions, then click 'Enter Answer'.

......!!!!!!!!...................................

RESPONSE -->

Answer to question is entered here, click enter responce.

Next click on next question.

If answer is incorrect student may critique his answer, Select Save as Notes, work will be saved in notes file.

Proceed by clicking enter response.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:27:44

Your answer has been noted. Enter 'ok' in the Response Box and click on Enter Response, then click on Next Question/Answer for the first real question.

......!!!!!!!!...................................

RESPONSE -->

OK

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:28:38

`q002. Note that there are 10 questions in this assignment. The questions are of increasing difficulty--the first questions are fairly easy but later questions are very tricky. The main purposes of these exercises are to refine your thinking about rates, and to see how you process challenging information. Continue as far as you can until you are completely lost. Students who are prepared for the highest-level math courses might not ever get lost.

If you make $50 in 5 hr, then at what rate are you earning money?

......!!!!!!!!...................................

RESPONSE -->

$10 per hour

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:29:57

`q004. Suppose that the $60,000 is made in a year by a small business. Would be more appropriate to say that the business makes $5000 per month, or that the business makes an average of $5000 per month?

......!!!!!!!!...................................

RESPONSE -->

Avg of 5K per month

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:30:33

01-30-2009 12:30:33

Small businesses do not usually make the same amount of money every month. The amount made depends on the demand for the services or commodities provided by the business, and there are often seasonal fluctuations in addition to other market fluctuations. It is almost certain that a small business making $60,000 per year will make more than $5000 in some months and less than $5000 in others. Therefore it is much more appropriate to say that the business makes and average of $5000 per month.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES ------->

.......................................................!!!!!!!!...................................

12:31:36

`q005. If you travel 300 miles in 6 hours, at what average rate are you covering distance, and why do we say average rate instead of just plain rate?

......!!!!!!!!...................................

RESPONSE -->

50 miles per hour

The rate is averaged due to increasing and decreasing speeds.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:32:02

01-30-2009 12:32:02

The average rate is 50 miles per hour, or 50 miles / hour. This is obtained by dividing the accumulated quantity, the 300 miles, by the time required to accumulate it, obtaining ave rate = 300 miles / ( 6 hours) = 50 miles / hour. Note that the rate at which distance is covered is called speed. The car has an average speed of 50 miles/hour. We say 'average rate' in this case because it is almost certain that slight changes in pressure on the accelerator, traffic conditions and other factors ensure that the speed will sometimes be greater than 50 miles/hour and sometimes less than 50 miles/hour; the 50 miles/hour we obtain from the given information is clearly and overall average of the velocities.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES ------->

.......................................................!!!!!!!!...................................

12:33:39

`q006. If you use 60 gallons of gasoline on a 1200 mile trip, then at what average rate are you using gasoline, with respect to miles traveled?

......!!!!!!!!...................................

RESPONSE -->

20 MPG

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:34:23

01-30-2009 12:34:23

The rate of change of one quantity with respect to another is the change in the first quantity, divided by the change in the second. As in previous examples, we found the rate at which money was made with respect to time by dividing the amount of money made by the time required to make it.

By analogy, the rate at which we use fuel with respect to miles traveled is the change in the amount of fuel divided by the number of miles traveled. In this case we use 60 gallons of fuel in 1200 miles, so the average rate it 60 gal / (1200 miles) = .05 gallons / mile.

Note that this question didn't ask for miles per gallon. Miles per gallon is an appropriate and common calculation, but it measures the rate at which miles are covered with respect to the amount of fuel used. Be sure you see the difference.

Note that in this problem we again have here an example of a rate, but unlike previous instances this rate is not calculated with respect to time. This rate is calculated with respect to the amount of fuel used. We divide the accumulated quantity, in this case miles, by the amount of fuel required to cover those miles. Note that again we call the result of this problem an average rate because there are always at least subtle differences in driving conditions that require the use of more fuel on some miles than on others.

It's very important to understand the phrase 'with respect to'. Whether the calculation makes sense or not, it is defined by the order of the terms.

In this case gallons / mile tells you how many gallons you are burning, on the average, per mile. This concept is not as familiar as miles / gallon, but except for familiarity it's technically no more difficult.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> I calculated MPG

.......................................................!!!!!!!!...................................

12:35:50

`q007. The word 'average' generally connotes something like adding two quantities and dividing by 2, or adding several quantities and dividing by the number of quantities we added. Why is it that we are calculating average rates but we aren't adding anything?

......!!!!!!!!...................................

RESPONSE -->

We already knew the summation and the quanity.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:36:19

01-30-2009 12:36:19

The word 'average' in the context of the dollars / month, miles / gallon types of questions we have been answering was used because we expect that in different months different amounts were earned, or that over different parts of the trip the gas mileage might have varied, but that if we knew all the individual quantities (e.g., the dollars earned each month, the number of gallons used with each mile) and averaged them in the usual manner, we would get the .05 gallons / mile, or the $5000 / month. In a sense we have already added up all the dollars earned in each month, or the miles traveled on each gallon, and we have obtained the total $60,000 or 1200 miles. Thus when we divide by the number of months or the number of gallons, we are in fact calculating an average rate.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> I think we agree

.......................................................!!!!!!!!...................................

12:39:28

`q008. In a study of how lifting strength is influenced by various ways of training, a study group was divided into 2 subgroups of equally matched individuals. The first group did 10 pushups per day for a year and the second group did 50 pushups per day for year. At the end of the year to lifting strength of the first group averaged 147 pounds, while that of the second group averaged 162 pounds. At what average rate did lifting strength increase per daily pushup?

......!!!!!!!!...................................

RESPONSE -->

Group 1 147/365/10=0.04 lbs per day

Group 2 162/365/50=0.0089 lbs per day

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:40:49

01-30-2009 12:40:49

The second group had 15 pounds more lifting strength as a result of doing 40 more daily pushups than the first. The desired rate is therefore 15 pounds / 40 pushups = .375 pounds / pushup.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> I missed the question.

I calculated lbs that each pushup added

.......................................................!!!!!!!!...................................

12:43:25

`q009. In another part of the study, participants all did 30 pushups per day, but one group did pushups with a 10-pound weight on their shoulders while the other used a 30-pound weight. At the end of the study, the first group had an average lifting strength of 171 pounds, while the second had an average lifting strength of 188 pounds. At what average rate did lifting strength increase with respect to the added shoulder weight?

......!!!!!!!!...................................

RESPONSE -->

188-171=17lb

30-10=20

17/20= 0.85lbs

confidence assessment: 1

.................................................

......!!!!!!!!...................................

12:43:48

01-30-2009 12:43:48

The difference in lifting strength was 17 pounds, as a result of a 20 pound difference in added weight. The average rate at which strength increases with respect added weight would therefore be 17 lifting pounds / (20 added pounds) = .85 lifting pounds / added pound. The strength advantage was .85 lifting pounds per pound of added weight, on the average.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> Correct

.......................................................!!!!!!!!...................................

12:45:05

`q010. During a race, a runner passes the 100-meter mark 12 seconds after the start and the 200-meter mark 22 seconds after the start. At what average rate was the runner covering distance between those two positions?

......!!!!!!!!...................................

RESPONSE -->

22s-12s=10s

200-100=100m

100/10=10ms

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:45:22

01-30-2009 12:45:22

The runner traveled 100 meters between the two positions, and required 10 seconds to do so. The average rate at which the runner was covering distance was therefore 100 meters / (10 seconds) = 10 meters / second. Again this is an average rate; at different positions in his stride the runner would clearly be traveling at slightly different speeds.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> correct

.......................................................!!!!!!!!...................................

12:50:57

`q011. During a race, a runner passes the 100-meter mark moving at 10 meters / second, and the 200-meter mark moving at 9 meters / second. What is your best estimate of how long it takes the runner to cover the 100 meter distance?

......!!!!!!!!...................................

RESPONSE -->

distance=100

runner is gradually declining in speed.

19 meters=2 seconds

100/19=5.26 seconds

confidence assessment: 1

.................................................

......!!!!!!!!...................................

12:51:45

01-30-2009 12:51:45

At 10 meters/sec, the runner would require 10 seconds to travel 100 meters. However the runner seems to be slowing, and will therefore require more than 10 seconds to travel the 100 meters. We don't know what the runner's average speed is, we only know that it goes from 10 m/s to 9 m/s. The simplest estimate we could make would be that the average speed is the average of 10 m/s and 9 m/s, or (10 m/s + 9 m/s ) / 2 = 9.5 m/s. Taking this approximation as the average rate, the time required to travel 100 meters will be (100 meters) / (9.5 m/s) = 10.5 sec, approx.. Note that simply averaging the 10 m/s and the 9 m/s might not be the best way to approximate the average rate--for example we if we knew enough about the situation we might expect that this runner would maintain the 10 m/s for most of the remaining 100 meters, and simply tire during the last few seconds. However we were not given this information, and we don't add extraneous assumptions without good cause. So the approximation we used here is pretty close to the best we can do with the given information.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES -------> I see the concept, but I did it wrong

.......................................................!!!!!!!!...................................

12:52:37

`q012. We just averaged two quantities, adding them in dividing by 2, to find an average rate. We didn't do that before. Why we do it now?

......!!!!!!!!...................................

RESPONSE -->

Because the quantity is decreasing at an assumed linear rate.

confidence assessment: 1

.................................................

......!!!!!!!!...................................

12:52:57

01-30-2009 12:52:57

In previous examples the quantities weren't rates. We were given the amount of change of some accumulating quantity, and the change in time or in some other quantity on which the first was dependent (e.g., dollars and months, miles and gallons). Here we are given 2 rates, 10 m/s and 9 m/s, in a situation where we need an average rate in order to answer a question. Within this context, averaging the 2 rates was an appropriate tactic.

You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.

......!!!!!!!!...................................

NOTES ------->

.................................................................................................

njY}

assignment #002

002. Describing Graphs

qa initial problems

02-03-2009

......!!!!!!!!...................................

12:18:54

`q001. You will frequently need to describe the graphs you have constructed in this course. This exercise is designed to get you used to some of the terminology we use to describe graphs. Please complete this exercise and email your work to the instructor. Note that you should do these graphs on paper without using a calculator. None of the arithmetic involved here should require a calculator, and you should not require the graphing capabilities of your calculator to answer these questions.

Problem 1. We make a table for y = 2x + 7 as follows: We construct two columns, and label the first column 'x' and the second 'y'. Put the numbers -3, -2, -1, -, 1, 2, 3 in the 'x' column. We substitute -3 into the expression and get y = 2(-3) + 7 = 1. We substitute -2 and get y = 2(-2) + 7 = 3. Substituting the remaining numbers we get y values 5, 7, 9, 11 and 13. These numbers go into the second column, each next to the x value from which it was obtained. We then graph these points on a set of x-y coordinate axes. Noting that these points lie on a straight line, we then construct the line through the points.

Now make a table for and graph the function y = 3x - 4.

Identify the intercepts of the graph, i.e., the points where the graph goes through the x and the y axes.

......!!!!!!!!...................................

RESPONSE -->

(-3,-13)

(-2,-10)

(-1,-7)

(0,-4)

(1,-1)

(2,2)

(3,5)

INTERCEPTS Y AXIS AT (0,-4), INTERCEPTS X AXIS AT (1.33,0)

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:19:43

The graph goes through the x axis when y = 0 and through the y axis when x = 0.

The x-intercept is therefore when 0 = 3x - 4, so 4 = 3x and x = 4/3.

The y-intercept is when y = 3 * 0 - 4 = -4. Thus the x intercept is at (4/3, 0) and the y intercept is at (0, -4).

Your graph should confirm this.

......!!!!!!!!...................................

RESPONSE -->

I gave the correct responce

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:20:39

`q002. Does the steepness of the graph in the preceding exercise (of the function y = 3x - 4) change? If so describe how it changes.

......!!!!!!!!...................................

RESPONSE -->

The rate of rise vs run does not change. It increases at the same rate.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:20:51

The graph forms a straight line with no change in steepness.

......!!!!!!!!...................................

RESPONSE -->

self critique assessment:

.................................................

......!!!!!!!!...................................

12:25:49

`q003. What is the slope of the graph of the preceding two exercises (the function ia y = 3x - 4;slope is rise / run between two points of the graph)?

......!!!!!!!!...................................

RESPONSE -->

Slope = (y2-y1)/(x2-x1)

(5-2)/(3-1)=3/2

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:27:04

Between any two points of the graph rise / run = 3.

For example, when x = 2 we have y = 3 * 2 - 4 = 2 and when x = 8 we have y = 3 * 8 - 4 = 20. Between these points the rise is 20 - 2 = 18 and the run is 8 - 2 = 6 so the slope is rise / run = 18 / 6 = 3.

Note that 3 is the coefficient of x in y = 3x - 4.

Note the following for reference in subsequent problems: The graph of this function is a straight line. The graph increases as we move from left to right. We therefore say that the graph is increasing, and that it is increasing at constant rate because the steepness of a straight line doesn't change.

......!!!!!!!!...................................

RESPONSE -->

I had my formula correct, but I plugged in the wrong coordinates.

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:29:34

`q004. Make a table of y vs. x for y = x^2. Graph y = x^2 between x = 0 and x = 3.

Would you say that the graph is increasing or decreasing?

Does the steepness of the graph change and if so, how?

Would you say that the graph is increasing at an increasing rate, increasing at a constant rate, increasing at a decreasing rate, decreasing at an decreasing rate, decreasing at a constant rate, or decreasing at a decreasing rate?

......!!!!!!!!...................................

RESPONSE -->

graph is increasing

steepness increases exponentially

graph is increasing at an increasing rate

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:32:20

Graph points include (0,0), (1,1), (2,4) and (3,9). The y values are 0, 1, 4 and 9, which increase as we move from left to right.

The increases between these points are 1, 3 and 5, so the graph not only increases, it increases at an increasing rate

STUDENT QUESTION: I understand increasing...im just not sure at what rate...how do you determine increasing at an increasing rate or a constant rate?

INSTRUCTOR RESPONSE: Does the y value increase by the same amount, by a greater amount or by a lesser amount every time x increases by 1?

In this case the increases get greater and greater. So the graph increases, and at an increasing rate. *&*&.

......!!!!!!!!...................................

RESPONSE -->

this borders on calculas,

the rate the rise increases will increase with run, for example at x=100 the y value would be 10k.

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:35:11

`q005. Make a table of y vs. x for y = x^2. Graph y = x^2 between x = -3 and x = 0.

Would you say that the graph is increasing or decreasing?

Does the steepness of the graph change and if so, how?

Would you say that the graph is increasing at an increasing rate, increasing at a constant rate, increasing at a decreasing rate, decreasing at an decreasing rate, decreasing at a constant rate, or decreasing at a decreasing rate?

......!!!!!!!!...................................

RESPONSE -->

-3,9

-2,4

-1,1

0,0

the graph is decreasing

the steepnes decreases with each increment of the x coordinate

the graph is decreasing at a decreasing rate.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:36:25

From left to right the graph is decreasing (points (-3,9), (-2,4), (-1,1), (0,0) show y values 9, 4, 1, 0 as we move from left to right ). The magnitudes of the changes in x from 9 to 4 to 1 to 0 decrease, so the steepness is decreasing.

Thus the graph is decreasing, but more and more slowly. We therefore say that the graph is decreasing at a decreasing rate.

......!!!!!!!!...................................

RESPONSE -->

I concur.

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:40:09

`q006. Make a table of y vs. x for y = `sqrt(x). [note: `sqrt(x) means 'the square root of x']. Graph y = `sqrt(x) between x = 0 and x = 3.

Would you say that the graph is increasing or decreasing?

Does the steepness of the graph change and if so, how?

Would you say that the graph is increasing at an increasing rate, increasing at a constant rate, increasing at a decreasing rate, decreasing at an decreasing rate, decreasing at a constant rate, or decreasing at a decreasing rate?

......!!!!!!!!...................................

RESPONSE -->

0,0

1,1

2,1.414

3,1.732

graph is increasing

the steepness of the graph increases but at a slower rate

increasing at a decreasing rate

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:40:55

If you use x values 0, 1, 2, 3, 4 you will obtain graph points (0,0), (1,1), (2,1.414), (3. 1.732), (4,2). The y value changes by less and less for every succeeding x value. Thus the steepness of the graph is decreasing.

The graph would be increasing at a decreasing rate.

If the graph respresents the profile of a hill, the hill starts out very steep but gets easier and easier to climb. You are still climbing but you go up by less with each step, so the rate of increase is decreasing.

If your graph doesn't look like this then you probably are not using a consistent scale for at least one of the axes. If your graph isn't as desribed take another look at your plot and make a note in your response indicating any difficulties.

......!!!!!!!!...................................

RESPONSE -->

I had the correct answers and graph

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:46:06

`q007. Make a table of y vs. x for y = 5 * 2^(-x). Graph y = 5 * 2^(-x) between x = 0 and x = 3.

Would you say that the graph is increasing or decreasing?

Does the steepness of the graph change and if so, how?

Would you say that the graph is increasing at an increasing rate, increasing at a constant rate, increasing at a decreasing rate, decreasing at an decreasing rate, decreasing at a constant rate, or decreasing at a decreasing rate?

......!!!!!!!!...................................

RESPONSE -->

the graph is increasing (going left to right

the graph's steepness increases at the same rate.

increasing at a constant rate.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:48:42

** From basic algebra recall that a^(-b) = 1 / (a^b).

So, for example:

2^-2 = 1 / (2^2) = 1/4, so 5 * 2^-2 = 5 * 1/4 = 5/4.

5* 2^-3 = 5 * (1 / 2^3) = 5 * 1/8 = 5/8. Etc.

The decimal equivalents of the values for x = 0 to x = 3 will be 5, 2.5, 1.25, .625. These values decrease, but by less and less each time.

The graph is therefore decreasing at a decreasing rate. **

......!!!!!!!!...................................

RESPONSE -->

I did not catch the notation.

It looked to me that you were saying 2^(-x) as 2 to the 2nd power times the negative value of x.

self critique assessment: 3

.................................................

......!!!!!!!!...................................

12:50:10

`q008. Suppose you stand still in front of a driveway. A car starts out next to you and moves away from you, traveling faster and faster.

If y represents the distance from you to the car and t represents the time in seconds since the car started out, would a graph of y vs. t be increasing or decreasing?

Would you say that the graph is increasing at an increasing rate, increasing at a constant rate, increasing at a decreasing rate, decreasing at an decreasing rate, decreasing at a constant rate, or decreasing at a decreasing rate?

......!!!!!!!!...................................

RESPONSE -->

The graph would be increasing and it would be increasing at an increasing rate.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

12:50:29

** The speed of the car increases so it goes further each second. On a graph of distance vs. clock time there would be a greater change in distance with each second, which would cause a greater slope with each subsequent second. The graph would therefore be increasing at an increasing rate. **

......!!!!!!!!...................................

RESPONSE -->

self critique assessment: 3

.................................................

&#Very good responses. Let me know if you have questions. &#