Compactness with open and closed intervals

Here we look at the concept of compactness and try to better understand it using intervals on the real number line.

[mohamedradwan]

Why I never came across such explanation under any definition of compactness on the internet? Why do I have to search so long to find such a simple example that finally makes the concept clear? Thank you sir !

[jueedhar]

Thanks a lot ! I just wasn't getting this all morning and now it seems all so clear

[avinashdongare]

Still I have doubt ..can you help me ?

[dr.qusayal-zamil]

Is [0, ∞) compact manifold with boundary?

[uttamsen]

sir give me concept of bolzano weietrass theorem of real number

[candykiss]

why not put the orange intervals near the endpoints for (0, 1) like you did for [0, 1]??

[josemiguelmalonda]

The sound is horrible, I
it's painful follow