Assignments 8

course Mth 163

assignment #008008.

Precalculus I

07-11-2008

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14:00:27

`q001. Note that this assignment has 4 questions

For the function y = 1.1 x + .8, what are the coordinates of the x = 2 and x = 9 points? What is the rise between these points and what is the run between these points? What therefore is the slope between these points?

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RESPONSE -->

For x = 2, y = 1.1*2 + .8 = 2.2 + .8 = 3

For x = 9, y = 1.1*9 + .8 = 9.9 + .8 = 10.7

We have the coordinates (2, 3) and (9, 10.7).

The rise between these two point is 10.7 - 3 = 7.7.

The run between these two points is 9 - 2 = 7.

The slope between these points is 7.7 / 7 =

1.1

confidence assessment: 1

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14:00:51

Evaluating y = 1.1 x +.8 for x = 2 and x = 9 we obtain y = 3 and y = 10.7. The graph points are therefore (2,3) and (9,10.7).

The rise between these points is 10.7 - 3 = 7.7 and the run is 9-2 = 7. Thus the slope is 7.7 / 7 = 1.1.

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RESPONSE -->

okay

self critique assessment: 3

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14:13:47

`q002. For the function y = 1.1 x + .8, what are the coordinates of the x = a point, in terms of the symbol a? What are the coordinates of the x = b point, in terms of the symbol b?

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RESPONSE -->

I'm not sure about the a point, but I do know that the function is y = mx + b, so b = .8. To solve for the coordinates, if x = b we find:

y = 1.1*.8 + .8 = .88 + .8 = 1.68 (.8, 1.68)

Or is the correct way of finding the coordinates doing:

y = 1.1*a + .8

confidence assessment: 0

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14:15:15

If x = a, then y = 1.1 x + .8 gives us y = 1.1 a + .8.

If x = b, then y = 1.1 x + .8 gives us y = 1.1 b + .8. Thus the coordinates of the x = a point are (a, 1.1 a + .8) and (b, 1.1 b + .8).

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RESPONSE -->

I made it harder than it really was.

self critique assessment: 3

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14:17:59

`q003. We see that the coordinates of the x = a point are (a, 1.1 a + .8) and (b, 1.1 b + .8). What therefore is the rise between these two points? What is the run between these two points?

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RESPONSE -->

The rise between the two coordinates would be:

(1.1b + .8) - (1.1a + .8) = 1.1b - 1.1a

The run between the two coordinates would be:

(b - a)

confidence assessment: 1

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14:18:38

The rise between the points is the rise from y = 1.1 a + .8 to y = 1.1 b + .8, a rise of

rise = (1.1 b + .8) -(1.1 a + .8) = 1.1 b + .8 - 1.1 a - .8 = 1.1 b - 1.1 a.

The run is from x = a to x = b, a run of

run = b - a.

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RESPONSE -->

I came to the same answer

self critique assessment: 3

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14:20:59

`q004. We see that the rise between the x = a and x = b points of the graph of y = 1.1x +.8 is 1.1 b + .8 - (1.1 a + .8), while the run is b - a. What therefore is the average slope of the graph between these points? Simplify your answer.

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RESPONSE -->

I believe the slope would be:

[(1.1b + .8) - (1.1a + .8)] / b - a =

(1.1b - 1.1a) / b - a = 0

confidence assessment: 0

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14:25:16

The slope is

slope = rise / run = (1.1 b - 1.1 a) / (b - a) = 1.1 (b - a) / (b - a) = 1.1.

The significance of this series of exercises is that the slope between any two points of the straight line y = 1.1 x + .8 must be 1.1, no matter whether the points are given by numbers (e.g., x = 2 and x = 9) or by symbols (x = a and x = b). Mostly

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RESPONSE -->

I wasn't sure about finding the slope of that type of function. I see why it is 1.1 instead of 0, I was suppose to divide it first before subtracting.

self critique assessment: 2

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assignment #008

008. `query 8 DERIVE exercise, Major Quiz ...

Precalculus I

07-15-2008

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10:04:34

Were you able to complete the DERIVE exercise?

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RESPONSE -->

I was not able to locate the trial on the TI web page for the DERIVE program, therefore I wasn't able to complete the exercise.

confidence assessment: 1

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10:06:06

Did you understand everything in the DERIVE exercise?

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RESPONSE -->

After reading what was to be done in the DERIVE exercise I see how the system is to be used and how it can help with equations and graphs.

confidence assessment: 1

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10:06:14

Do you have any questions about the DERIVE exercise?

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RESPONSE -->

no

confidence assessment: 1

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VTDg˞Vw

Good work.

Don't worry about the DERIVE exercise.