Oreintation Part III

course Mth 173

assignment #001001. typewriter notation

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

qa initial problems

06-10-2007

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01:25:35

`q001. Explain the difference between x - 2 / x + 4 and (x - 2) / (x + 4). The evaluate each expression for x = 2.

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RESPONSE -->

The order of opperations indicates which operations must be performed first.

It makes a difference as to whether whether or not you subtract the 2 from the x or divide the -2 by 4 first. If you don't have parentheses you have to divide before you subtract. Substituting 2 for x we get 2 - 2 / 2 + 4 = 2 - 1 + 4, then you come out with an answer of 5.

By using parentheses, we have a completely different answer:

(x - 2) / (x - 4) = (2 - 2) / ( 4 - 2) = 0 / 2 = 0

confidence assessment: 2

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01:32:08

`q002. Explain the difference between 2 ^ x + 4 and 2 ^ (x + 4). Then evaluate each expression for x = 2.

Note that a ^ b means to raise a to the b power. This process is called exponentiation, and the ^ symbol is used on most calculators, and in most computer algebra systems, to represent exponentiation.

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RESPONSE -->

2 ^ x + 4 shows that we are to raise 2 to the x power before adding 4.

2 ^ (x + 4) shows that we are to first perform find the sum of x + 4, then raise 2 to the discovered power.

If x = 2, then we get 2 ^ x + 4 = 2 ^ 2 + 4 = 2 * 2 + 4 = 4 + 4 = 8.

On the other hand, 2 ^ (x + 4) = 2 ^ (2 + 4) = 2 ^ 6 = 2*2*2*2*2*2 = 64.

confidence assessment: 2

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01:53:54

`q003. What is the numerator of the fraction in the expression x - 3 / [ (2x-5)^2 * 3x + 1 ] - 2 + 7x? What is the denominator? What do you get when you evaluate the expression for x = 2?

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RESPONSE -->

The numerator would be 3, since it is not enclosed with x in parentheses.

The denominator is [ (2x-5)^2*3x+1].

Evaluating x - 3 / [ (2x-5)^2 * 3x + 1 ] - 2 + 7x:

2-3/ [ (2(2)-5)^2 * 3(2)+1] -2+7(2)=

2-3/ [ (-1)^2 * 7] -2 + 14=

2-3/7 -2 + 14=

14/2-3/7-14/7+98/7=

95/7

confidence assessment: 2

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02:03:54

`q004. Explain, step by step, how you evaluate the expression (x - 5) ^ 2x-1 + 3 / x-2 for x = 4.

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RESPONSE -->

Evaluating (x-5)^2x-1 + 3/x-2, x=4:

[(4)-5]^2 *(4)-1 + 3/(4) -2=

(-1)^2 * 3 +3/4 -2=

3 + 3/4 -2=

7/4

confidence assessment: 2

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02:08:04

*&*& Standard mathematics notation is easier to see. On the other hand it's very important to understand order of operations, and students do get used to this way of doing it.

You should of course write everything out in standard notation when you work it on paper.

It is likely that you will at some point use a computer algebra system, and when you do you will have to enter expressions through a typewriter, so it is well worth the trouble to get used to this notation.

Indicate your understanding of the necessity to understand this notation.

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RESPONSE -->

Understanding notation is critical in this coarse, because the slightest misinterpretation can give you an entirely different answer.

self critique assessment: 1

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02:11:25

`q005. At the link

http://www.vhcc.edu/dsmith/genInfo/introductory problems/typewriter_notation_examples_with_links.htm

(copy this path into the Address box of your Internet browser; alternatively use the path

http://vhmthphy.vhcc.edu/ > General Information > Startup and Orientation (either scroll to bottom of page or click on Links to Supplemental Sites) > typewriter notation examples

and you will find a page containing a number of additional exercises and/or examples of typewriter notation.Locate this site, click on a few of the links, and describe what you see there.

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RESPONSE -->

You can some instructions and over 30 examples. Clicking on the word Picture, you will see the standard-notation format. The link ""Examples and Pictures"", in the initial instructions, shows examples and pictures without having to click on it.

confidence assessment: 2

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end of document

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