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WEBVTT
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Ortez said said it's a collection of some data you can think about it as a box containing some object.
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So for example if I have box that contains numbers 8 4 6 and 0 in mathematic the boxes said and 8 4
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6 and 0 are elements of this set.
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And we usually use this notation.
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So we use braces these braces define set and inside these braces we write our elements and we separate
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them with comma and we can also call every set by its name.
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So for example does this set A.
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And it contains 8 4 6 and 0.
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Another thing I need to mention is that sets are unordered.
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What that means.
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Well if you take a box and fill it with numbers it doesn't matter what number is most right.
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All we care about is if the number is in the box.
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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
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that has been set B is also in set A and every element that is inside a is also in B.
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So it doesn't matter in what order the elements are.
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All we care about is whether the elements are in set.
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Another important thing is that we don't have repeating elements.
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So for example if I define set C that contains 8 4 6 0 and 8 it is still equal to set a y.
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Once again we care only about whether the element is in set and we don't care how many times it isn't
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said.
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OK.
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Now let's talk about the ways to define set we can do it simply by writing out all the elements inside
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braces.
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But sometimes we have an infinite set.
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And obviously you can't just write all the elements inside braces.
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So we define these sets using their characteristic property.
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And what do I mean by that we can say that this set will contain all the prime numbers.
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For those of you who don't know what prime number is it is just number that we can divide only by 1
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and itself.
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In this case you can use natural language to describe this.
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You can write it like this.
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So braces and inside X from an where and represents that of natural numbers.
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So numbers like 1 2 free and so on to infinity for example two point five zero or minus five is not
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in the set.
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There are only positive integers and then there is this kind of separator.
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And here we define what this X should look like.
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If we use natural language we can just write.
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X is prime number and we are done.
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But sometimes natural language can be misleading.
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So some mathematical description is often used for example like this.
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So this set is containing every x that is from natural numbers and also is true that for every I that
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is from natural numbers if X modulo Y is equal to zero then I's equal one or equal to x.
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So that is how mathematic definition could look like.
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So something's up said is a collection of data objects inside of a set are called elements to define
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said we as racists and inside them we write all the elements or we write characteristic property.
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Also it doesn't matter what order the elements are and how many times they are in set.
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Also set can contain numbers but it can also contain string or anything else.
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So that is all there is to it.
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If you have any questions just ask and I will see you next time.
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