Hello everyone! We just started set theroy and i just need to make sure i'm right about this...(adsbygoogle = window.adsbygoogle || []).push({});

THe question says:

Indicate the elements in each set dfined in a-f.

e. W = {t is in Z | -1 < t < -3 }

f. X = { u in Z | u <= 4 or u >= 1 }

for e. I said it would be No elemnts in the set, becuase there is no overlapping if you draw it on a number line nor is it possible to be greater than -1 and also be less than -3.'

for f.

i said {1,2,3,4}

but is this wrong because its an or problem, if its or, does that mean its all Z every integer is in the set? I think its Z everything intger is in the set now that i type this...

also for b.

T = { m is in Z | m = 1 + (-1)^i, for some integer i}

{ 0, 2}

#2.

is O with a cross through it, the null set an element of {NULL SET}?

I said no becuase the null set has no elements, its an empty set. So an empty set cannot be in a set with only 1 element, {NULL SET}

#3.

Is NULL set an element of Null set?

This one confused me...

its like saying is 2 in 2...

I said yes, because a an empty element is equal to an empty element like 2 is equal to 2...or am i misunderstanding this? I know if A is a subset of B and B is a sebset of A then A = B. But in this case its not saying they are subsets....they are uusing the "in" notation that looks like a small e.

thanks!

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# Homework Help: Easy set question, is this right?

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