course Mth151 J???M?R??????k?????assignment #001
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13:12:22 `questionNumber 20000 2.2.24 U={a,b,...,g}, A={a,e}, B={a,b,e,f,g}, C={b,f,g}, D={d,e} Is C ps U? Is the statement true or false and why?
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RESPONSE --> This is a true statement because U= a, b, c, d, e, f, g and c= b, f, g since all the letters in c are also contained in u and u has more letters not included in c then c is a subset of u confidence assessment: 2
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13:12:34 `questionNumber 20000 ** It's true because all elements of C are in the universal set, and because there are elements of U that aren't in C. You have to have both conditions, since a proper subset cannot be identical to other set. **
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RESPONSE --> ok self critique assessment: 3
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13:16:33 `questionNumber 20000 Query 2.2.30 phi s D
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RESPONSE --> psi is a subset but not a proper subset confidence assessment: 2
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13:17:48 `questionNumber 20000 ** Note that You should be responding to problem 2.2.30 from the homework you worked out on paper. The shorthand notation is for my reference and won't always make sense to you. For clarification, though, the symbol for the empty set is the Greek letter phi. One set is a subset of another if every element of that set is in the other. To show that a set isn't a subset of another you have to show something in that set that isn't in the other. There's nothing in the empty set so you can never do this--you can never show that it has something the other set doesn't. So you can never say that the empty set isn't a subset of another set. Thus the empty set is a subset of any given set, and in particular it's a subset of D. ALTERNATIVE ANSWER: As the text tells you, the empty set is a subset of every set. ANOTHER ALTERNATIVE Every element of the empty set is in D because there is no element in the empty set available to lie outside of D. ONE MORE ALTERNATIVE: The empty set is a subset of every set. Any element in an empty set is in any set, since there's nothing in the empty set to contradict that statement. **
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RESPONSE --> ok self critique assessment: 2
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11:45:30 `questionNumber 20000 2.2.33 D not s B Is the statement true or false and why?
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RESPONSE --> The statement is true because set D contains the letter d and set B does not contain a d so it is not a subset confidence assessment: 1
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