Query 11

#$&*

course Mth 151

2/15 11:21

2 If your solution to stated problem does not match the given solution, you should self-critique per instructions at

http://vhcc2.vhcc.edu/dsmith/geninfo/labrynth_created_fall_05/levl1_22/levl2_81/file3_259.htm

Your solution, attempt at solution. If you are unable to attempt a solution, give a phrase-by-phrase interpretation of the problem along with a statement of what you do or do not understand about it. This response should be given, based on the work you did in completing the assignment, before you look at the given solution.

013. `query 13

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Question: `q3.2.6 ~(p^q) false; truth values of components

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution: both p and q would have to be true for their negation to be false. P and q are true.

confidence rating #$&*: 3

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Given Solution:

`a**The question asks for the truth values of p and q that would make the statement ~(p^q) false. If ~(p^q) is false then p^q is true, which means that both p and q must be true.**

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Self-critique (if necessary):

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Self-critique Rating: 3

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Question: `q3.2.18 p false q true ~[(~p^~q) U ~q]

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Your solution:

~[(~p^~q) U~q]

~ [(T^F) U F]

~[FUF]

~F

T

The equation is True.

confidence rating #$&*: 3

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Given Solution:

`a**~p ^ ~q is false because ~q is false. One false is fatal to a conjunction.

~q is false so both parts of the disjunction [(~p^~q) U ~q] are false. Thus [(~p^~q) U ~q] is false.

The negation ~[(~p^~q) U ~q] of this statement is therefore true.**

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Self-critique (if necessary):

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Self-critique Rating: 3

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Question: `q3.2.36 p: 15<8 q: 9 not > 5 r: 18 <= 18 evaluate -(p U -q) U -r

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Your solution: ~ (p U ~q) U ~r

~(F U T) U F

~T U F

F U F

F

The value of the statement is false.

confidence rating #$&*: 3

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Given Solution:

`a** p and q are both false statements, while r is a true statement.

It follows that p U ~q is true: since ~q is true the disjunction is true.

It therefore follows that ~(p U ~q) is false.

Since r is true, ~r is false.

Thus ~(p U ~q) U ~r is a disjunction of two false statements, ~(p U ~q) and ~r.

A disjunction of two false statements is false.

So the statement is false. **

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Self-critique (if necessary):

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Self-critique Rating: 3

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Question: `q (formerly 3.2.42) This wasn't assigned, but you should be able to answer based on your responses to similar assigned questions. {}{}How many rows are there in a statement involving p,q,r,s,u,v,m,n? Note that rows go across the page. For example a statement involving just p and q will have four rows, one each for TT, TF, FT and FF. The headings (i.e., p, q and whatever other statements are necessary to evaluate the truth table) might also be considered a row, but for this problem do not consider the headings to be a row.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution: 2 to the power of n is the answer. N=8. Therefore 2 to the power of 8 equals 256 rows.

confidence rating #$&*: 2

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Given Solution:

`a** If you just have two statements p and q, then there are four possible truth values: TT, TF, FT and FF.

If you have three statements p, q and r then there are eight possible truth values: TTT, TTF, TFT, TFF, and FTT, FTF, FFT, FFF.

Note that the number of possible truth values doubles every time you add a statement.

The number of truth values for 2 statements is 4, which is 2^2.

For 3 statements this doubles to 8, which is 2^3.

Every added statement doubles the number, which adds a power to 2.

From this we see that the number of possible truth values for n statements is 2^n.

For the 8 statements listed for this problem, there are therefore 2^8 =256 possible truth values. **

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Self-critique (if necessary):

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Self-critique Rating: 3

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Question: `q3.2.56 (fomerly 3.2.54) This was not assigned but based on your work on similar problems you should be able to construct the truth table for (-p ^ -q) U (~p U q). Give your truth table:

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Your solution:

P q (~p^~q) U (~p U q)

T T F F F T F T T

T F F F T F F F F

F T T F F T T T T

F F T T T T T T F

confidence rating #$&*: 2 I sure hope it’s right. That was too much trouble! : )

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Given Solution:

`a** For column headings

p q ~p ~q ~p^~q ~p U q (~p^~q) U (~p Uq)

the first row would start off T T, for p and for q. Then F F for ~p and ~q. Then F for ~p ^ ~q, then T for ~p V q, then T for the final column.

So the first row would be

T T F F F T T.

The second row would be

T F F T F F F

The third row would be

F T T F F T T

and the fourth row would be

F F T T T T T **

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Self-critique (if necessary): Ummm… I don’t know.

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Self-critique Rating:

@&

You got it.

You set up your truth table in an equivalent but slightly different way than in the given solution. Either way is perfectly valid.

*@

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Question: `q3.2.68 (formerly 3.2.66) This wasn't assigned but is similar to other assigned problems so you should be able to solve it: Negate the following statement using De Morgan's Law: ' F.C. tried to sell the wine but was unable to do so'.

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Your solution: ~(p ^ q ), ~p U ~q

Food City didn’t try to sell the wine, or They sold the wine.

confidence rating #$&*: 2

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Given Solution:

`a** We use two ideas here. The first is that 'but' is interpreted as 'and'; and the second is that the negation of an 'and' statement is an 'or' statement. deMorgan's Laws say that the negation of p OR q is ~p AND ~q, while the negation of p AND q is ~p OR ~q.

The given statement ' F.C. tried to sell the book but was unable to do so' can be symbolized as 'p ^ q'. Its negation would be ~(p ^ q) = ~p U ~q. We translate this as 'F.C. didn't try to sell the book or he sold it', or something equivalent. **

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Self-critique (if necessary):

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Self-critique Rating: 3

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Question: `q3.2.81 is the statement 3 + 1 = 6 xor 2 + 5 = 7 true or false?

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Your solution: It is True because in an “or” statement, if one is true then the whole statement is true.

confidence rating #$&*: 3

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Given Solution:

`a** For an XOR statement exactly one part has to be true. The statement is true because the second part is true and the first is false.

We need exactly one true statement; if both parts were true the XOR wouldn't be. **

I did pretty good this time!!! Yay!

"

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Self-critique (if necessary):

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Self-critique rating:

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Question: `q3.2.81 is the statement 3 + 1 = 6 xor 2 + 5 = 7 true or false?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution: It is True because in an “or” statement, if one is true then the whole statement is true.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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Given Solution:

`a** For an XOR statement exactly one part has to be true. The statement is true because the second part is true and the first is false.

We need exactly one true statement; if both parts were true the XOR wouldn't be. **

I did pretty good this time!!! Yay!

"

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Self-critique (if necessary):

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Self-critique rating:

#*&!

&#Your work looks good. See my notes. Let me know if you have any questions. &#