Write ⊆ or ⊄ in the space provided.

[KOO]

Write ⊆ or ⊄ in the space provided.

(3,5) _____ [3,5]
[-1,4] ____ (-1,4)
{∅} _____ P(∅)
N * Z ____ Z * N


My Solution)

⊆
⊄
⊄
⊆

 

[Klaas van Aarsen]

Write ⊆ or ⊄ in the space provided.

(3,5) _____ [3,5]
[-1,4] ____ (-1,4)
{∅} _____ P(∅)
N * Z ____ Z * N


My Solution)

⊆
⊄
⊄
⊆

Hi KOO!

The first 2 are correct.

Edit: see Evgeny.Makarov's post for the 3rd.

As for the 4th, can I assume you intended $\mathbb N \times \mathbb Z \underline{\qquad} \mathbb Z \times \mathbb N$?
If so then the left hand side has elements like (1,1) and (1,-1), while the right hand side has elements like (-1,1) and (1,1)...

 

[Evgeny.Makarov]

I assume the first two questions are about intervals on the real line. Then I agree.

{∅} _____ P(∅)

Note that P(∅) = {∅}.

 

[Klaas van Aarsen]

Note that P(∅) = {∅}.

Good point.
Slipped on that one.