Needing some help with Discrete

[Angrboda]

That's just whack. I changed my mind. I no longer want to go back to college and relearn all my math again.

[SavageNerdz]

Hmm i just find it strange it was asking for the amount of elements and the answer is actually the subsets present. Thank you Alex! I may have more questions to post if only my teacher broke it down like that..

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Ok here's another one i've no clue where to start as it wasn't covered in class:

2.1.43. Find the truth set of each of these predicates where the domain is the set of integers.

P(x): x2 < 3
Q(x): x2 > x
c) R(x): 2x + 1 = 0

[Alex K]

Thats the definition of P:the set of all the subsets. Its size is thus the number of subsets.

Anyways, you're welcome

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That's just whack. I changed my mind. I no longer want to go back to college and relearn all my math again.

Don't be too hard on yourself, this is horribly confusing

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Fun fact about P: if you stick an infinite set in, you get again an infinite set, but with a larger infinity than the first.

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Hmm i just find it strange it was asking for the amount of elements and the answer is actually the subsets present. Thank you Alex! I may have more questions to post if only my teacher broke it down like that..

---

Ok here's another one i've no clue where to start as it wasn't covered in class:

2.1.43. Find the truth set of each of these predicates where the domain is the set of integers.

P(x): x2 < 3
Q(x): x2 > x
c) R(x): 2x + 1 = 0

What's x2 suppposed to be?

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I think you're simply supposed to give all the integer values for x such that these inequalities hold...

So for the last it's the empty set {} cause theres no integer where twice itself gives -1

If by x2 you mean x squared, well, -1 squared is smaller 3, 0 squared is smaller, 1 squared is smaller, and that's it. So the first set is {-1,0,1} i guess...

[SavageNerdz]

Thats the definition of P:the set of all the subsets. Its size is thus the number of subsets.

Anyways, you're welcome

---

That's just whack. I changed my mind. I no longer want to go back to college and relearn all my math again.

Don't be too hard on yourself, this is horribly confusing

---

Fun fact about P: if you stick an infinite set in, you get again an infinite set, but with a larger infinity than the first.

---

Hmm i just find it strange it was asking for the amount of elements and the answer is actually the subsets present. Thank you Alex! I may have more questions to post if only my teacher broke it down like that..

---

Ok here's another one i've no clue where to start as it wasn't covered in class:

2.1.43. Find the truth set of each of these predicates where the domain is the set of integers.

P(x): x2 < 3
Q(x): x2 > x
c) R(x): 2x + 1 = 0

What's x2 suppposed to be?

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I think you're simply supposed to give all the values for x such that these inequalities hold...

Once again the values are not given, going to get to class early tomorrow and ask my professor how the hell i'm supposed to do this.. He didn't even cover it T.T

[Alex K]

What do you mean the values are not given?

Ok so I solved the first and last above... The second one is an infinite set I suppose.
{All integers excluding 0 and 1}

[SavageNerdz]

What do you mean the values are not given? I just solved the first and last... The second one is an infinite set I suppose.
{All integers excluding 0 and 1}

Just meant i didn't know what x2 was supposed to be. Literally before today i've never seen this despite being in class every day... Alex, out of curiosity are you majoring in comp. Sci.?

[Alex K]

No, unfortunately not (i wish I was young enough to go to college), but I do have a PhD in theoretical physics,insomnia and a smartphone with wifi

Do they literally write x2? Maybe they mean squared and the 2 is written a bit low

[SavageNerdz]

Here's a picture, the assignment is posted using blackboard:

[Alex K]

I think it prolly just means squared and he was too lazy to properly type it out...

[SavageNerdz]

I think it prolly just means squared and he was too lazy to properly type it out...

That makes a lot more sense... Do you have any advice for this course? I've been struggling with it since day one.