Original subtitles

Ortez said said it's a collection of some data you can think about it as a box containing some object.

So for example if I have box that contains numbers 8 4 6 and 0 in mathematic the boxes said and 8 4

6 and 0 are elements of this set.

And we usually use this notation.

So we use braces these braces define set and inside these braces we write our elements and we separate

them with comma and we can also call every set by its name.

So for example does this set A.

And it contains 8 4 6 and 0.

Another thing I need to mention is that sets are unordered.

What that means.

Well if you take a box and fill it with numbers it doesn't matter what number is most right.

All we care about is if the number is in the box.

So for example if I create set B that contains 0 8 4 and 6 it is the same as set a Y because every element

that has been set B is also in set A and every element that is inside a is also in B.

So it doesn't matter in what order the elements are.

All we care about is whether the elements are in set.

Another important thing is that we don't have repeating elements.

So for example if I define set C that contains 8 4 6 0 and 8 it is still equal to set a y.

Once again we care only about whether the element is in set and we don't care how many times it isn't

said.

OK.

Now let's talk about the ways to define set we can do it simply by writing out all the elements inside

braces.

But sometimes we have an infinite set.

And obviously you can't just write all the elements inside braces.

So we define these sets using their characteristic property.

And what do I mean by that we can say that this set will contain all the prime numbers.

For those of you who don't know what prime number is it is just number that we can divide only by 1

and itself.

In this case you can use natural language to describe this.

You can write it like this.

So braces and inside X from an where and represents that of natural numbers.

So numbers like 1 2 free and so on to infinity for example two point five zero or minus five is not

in the set.

There are only positive integers and then there is this kind of separator.

And here we define what this X should look like.

If we use natural language we can just write.

X is prime number and we are done.

But sometimes natural language can be misleading.

So some mathematical description is often used for example like this.

So this set is containing every x that is from natural numbers and also is true that for every I that

is from natural numbers if X modulo Y is equal to zero then I's equal one or equal to x.

So that is how mathematic definition could look like.

So something's up said is a collection of data objects inside of a set are called elements to define

said we as racists and inside them we write all the elements or we write characteristic property.

Also it doesn't matter what order the elements are and how many times they are in set.

Also set can contain numbers but it can also contain string or anything else.

So that is all there is to it.

If you have any questions just ask and I will see you next time.