This video tutorial covers fundamental set theory concepts including union (A ∪ B = collection of all elements from both sets), intersection (A ∩ B = collection of common elements), and difference (A - B = elements in A but not in B). The instructor explains key properties: commutative (A ∪ B = B ∪ A, A ∩ B = B ∩ A), associative ((A ∪ B) ∪ C = A ∪ (B ∪ C)), identity (A ∪ ∅ = A, A ∩ U = A), and distributive properties (A ∪ (B ∩ C) = (A ∪ B) ∩ (A ∪ C)). The universal set (U) contains all relevant elements for a given context, and the empty set (∅) contains no elements. The difference operation is neither commutative nor associative, unlike union and intersection.
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Day 26 - CRACK SSC MATHS by DEO, Nizamabad Sri P.Ashok garuAdded:
I for >> good morning sir.
>> Good morning.
>> Sm first step.
>> No no no sin square theta plus fourth fourth and fifth set.
Sin square theta + sin square theta= 1 square= 1 - cos² theta square theta= 1 - sin square theta then cos x² theta - square theta = 1 cos x square theta = 1 square theta = cos x square theta - 1 square tan square theta = 1 square theta = 1 square theta = 1 + tan tan square theta tan square theta = square theta - 1. Then se square theta + tan square theta into se square theta tan square theta = 1 theta + tan theta into se theta + tan theta into se theta tan theta = 1 theta tan theta = 1 theta + tan theta or se theta tan theta = 1 theta + tan theta then cos x² theta cosec theta minus co theta into cosec theta + theta = 1 cosec theta + theta or cosec= 1x cosec theta theta >> correct public tell the points of set a set is a collect uh uh collection of well design defined objects.
>> A set contains elements. The set contains elements. Uh there are three types of sets.
>> Infinite set uh uh finite set and uh empty set.
>> Infinite finite set means uh a set which has countable elements. Infinite set mean >> fixed number of elements.
>> Uh infinite set means a set which has uh not fixed elements. We can we can't count them.
>> Uh empty set means a set which which doesn't have any element.
>> Uh cardial number. Cardial number means the number of elements present in a set is known as cardinal number.
Uh >> Union.
Okay.
What is it?
Hello.
>> Hello. Yes sir. Union of two sets >> sir. Uh if A and B are any two sets then union of A and B is denoted with A union B >> right?
>> And defined as collection of all elements of A and B.
>> Right.
Elements of elements of sets elements of sets are written with small letters. Uh >> elements of sets are written with small letters. Uh the name of set is written with capital letter.
>> Right? We list all the we write all the elements of the set we separated with commas and put in bracket. Right? H >> in a curve bracket.
>> Right.
Right. That is actually order is not important not important in writing elements.
>> Yes sir.
>> Order is not important. I uh >> Repetition is not not repetition is not necessary right?
>> Yes sir.
>> Is not necessary right?
>> Yes sir. Repetition is not necessary.
Okay.
It's been Okay.
We discussed about union of two set right?
>> Yes sir.
>> How to write a union and b write all the elements of a and write all the elements of b >> elements of b.
>> Then we will get a union and set right.
>> Yes sir.
A= ABC.
>> What you will get?
>> ABC.
>> ABC. Sir, >> ABC. Union >> ABC. A B C >> write all the elements of A and all the elements of A >> elements of B. We not need repeatation.
So ABC >> therefore A is equal to A.
>> This is called as important property as properties of union.
Number one, commutative property.
>> A union B is equal to >> that is called asative property. Right?
>> Yes sir. Next associative property.
A union of B is equal to A >> see A union of B union C equal to A union B union C. This we proved right?
>> Yes. Yes sir.
>> Identity property union empty setal empty set union= right. Yes sir.
>> That is identity property and important property right.
>> Yes sir.
>> Got it.
>> Yes sir.
>> Next.
Intersection of >> What is the next concept?
>> Intersection of two sets.
>> Two sets.
>> Two sets.
A comma b any two sets.
Then their intersection intersection of A is denoted with A section B.
This is inverted U right?
>> Okay sir.
inverted U. That is the symbol intersection A intersection of B.
>> How to read?
>> A intersection B.
>> A intersection of B. A intersection B.
Right.
>> Yes sir.
>> Yes sir.
can be defined as as the set of all common.
Set of all common elements of a comma bir.
>> Got it.
>> Yes sir.
>> Yes sir.
>> Yes sir.
>> The set of all common elements of a comma b is denoted with a intersection b. Got it?
Yes sir. Yes sir.
>> Say the example.
>> 1 2 3 B = 2 3 4 Action.
What is it?
1 2 3.
>> What is it? 2 3a 4 >> which are common elements >> 2 and 3 2 and three and 2 3 are common elements right?
>> Yes sir.
>> Set consisting set consisting these common elements is called as a intersection b. Got it?
>> Okay sir. Yes sir. Yes sir. That 2 3 is a intersection b. Got it?
>> Yes sir.
>> Yes sir.
Point number one, B intersection. Number two, B intersection.
What is B intersection?
First you have >> 2a 3 2a 3 3a 4 intersection of 1a 2a 3 >> 1 2a 3 >> 1 2a 3 >> which is common intersection is also 2a 3 >> A intersection B and B intersection is same or not.
>> Yes sir.
Therefore, Action Balction is committed to >> Yes sir.
>> property, right?
>> Yes sir.
>> Intersection is got it >> sir.
Perfection means set of proper elements only right?
>> Yes sir.
>> Yes sir.
>> Example P intersection.
What is intersection Q?
>> A B C A B C D C D >> intersection intersection A D F A F A F A F A F A F A F A F A F A F A G A D F G >> A F G >> What are the common elements?
>> A and D A is common and D is common, right?
>> Yes sir. Yes sir. It is nothing but a d intersection.
>> Yes.
>> Got it.
>> Yes sir.
>> Yes sir.
>> This is the concept of intersection. It is set up on common elements only.
Right.
>> Yes sir.
How many members understood this intersection concept? Please raise your hand.
She's already No question about this.
Please cohost me sir.
>> Who sir?
>> Okay.
>> Thank you sir. Right.
Yes.
>> Yes. Got it. Is it my screen? My screen is visible.
>> Yes sir.
>> Yes sir. Yes sir.
>> Is very simple concept, right?
>> Yes sir. Yes sir.
Yes. Read the question.
A = 1A 2a 3 = 2 2a 3a 4a 5 = 3a 5a 6 find a union b a union of b union >> it is not union it is not union intersection a intersection of b intersection c uh b a intersection of >> intersection of B intersection C.
You have to read it as A intersection of B intersection C. Second one is A intersection B of intersection C.
>> Intersection C. Right? First one check A intersection of B intersection C. To find that one, what do I have to find? B intersection C. We have to find, right?
>> Yes, sir.
>> Yes. H.
>> How to write? What is B? 2a 3 intersection. What is 3a 5?
>> What are the common elements?
>> 3a 5 >> 3a 5 common elements, right?
>> Yes sir.
>> Two intersection is 3a 5. Right?
>> Yes sir.
>> Yes sir.
>> Intersection C is 3a 5. Right?
>> Yes sir.
>> Yes sir.
Next. A intersection.
What is set A >> B intersection C?
>> 3 5 >> 3 is the common element, right?
>> Yes sir. A intersection of B intersection C is three, right?
>> Yeah.
>> This is A intersection of B intersection C. First one.
>> What is the second one? A intersection B of intersection C.
>> What do I have to find first?
>> A intersection B.
>> What is A intersection A? Set 1 2 3.
Right?
>> Yes, sir.
>> Yes, sir.
>> What is B?
43 right?
>> Yes sir.
>> Yes sir.
>> What are the common elements?
>> 2 and three are common elements.
>> 2 and three are common elements.
>> 2 and 3 = 2.
>> A intersection B intersection C.
>> What is the intersection B? 2A 3. Right.
>> 2A 3.
>> What is C? intersection 3A 5 >> 3a 5a 6 >> 3a 5a 6 right >> yes sir >> yes sir >> yes what are the common elements >> only common element >> intersection equal to three >> same or not both of them are same or not >> yes sir yes sir >> what is your our conclusion a intersection Yes. Associative, right?
>> Yes. Yes, sir.
>> Yes, sir.
>> Associative.
>> Associative.
Intersection of sets is associative right? Associate.
>> Yes sir. Yes sir.
I'm not sure.
>> Yes, sir.
>> Yes, sir.
>> Good night.
Wait for one minute.
>> Thanks.
What is the definition? Next definition is >> universal set.
>> Universal set.
>> Universal set.
is the comprehensive collection of comprehensive collection of >> all elements relevant to particular ular situation, particular contest or situation.
>> As what is the definition of universal set?
>> Universal set is the comprehensive collection of all elements relevant to the particular context.
context or situation anything you can write.
>> Okay.
>> It is denoted with >> mu that set is denoted with >> mu >> mu that is un universal set mu universal set mean it collects all elements relating to a situation right?
>> Yes sir. Yes sir. H for example.
Example set is students of >> JPHS bin. What is it?
>> Student of JPHs.
set B is >> students of NPHs knowledge.
What is NB?
>> Students of JPs.
>> We have these two these two sets. One is set students of Ben. Set is >> students of universal.
>> Okay sir.
>> Nip mandal covers binola and knowledge or not.
>> Yes sir.
>> Yes sir. Perfect model students means it includes it includes knowledge for this one access universal set all right.
>> Yes sir.
>> Yes sir.
>> Any big set also you can take students of then also it acts as universal set right?
>> Yes sir.
>> Yes sir.
>> Students of cover these two schools or not?
>> Yes sir. Yes sir.
>> Otherwise students of Telangan also universal set right?
>> Yes sir.
particular situation collecting all the elements of that particular situation is called as universal set. Got it?
>> Yes sir.
>> Yes sir.
>> Is it clear?
>> Yes sir.
Is it clear? Set A is what?
>> A B C >> A B C >> corresponding to this set. This one is universal set. Is it? Is it correct?
>> Yes sir.
>> Yes sir.
This is your >> Yes sir.
>> Yes sir.
>> Yes sir.
>> A intersection m intersection >> intersection.
Uh what is intersection section A B C D C D E >> What you will get?
>> A B C >> A B C >> ABC Sir ABC.
>> Yes sir.
>> Yes sir.
Intersection is equal to only right only right?
>> Yes sir.
>> Number two intersection A intersection.
>> What is >> A B C D A B C D E intersection A B C >> What do you get? What are the common elements? A B A B C >> Yes sir.
>> A B C >> A B >> This is also equal to A only right?
>> Yes sir.
>> Therefore intersection = m= >> identity identity >> identity >> with respect to intersection.
We access identity with respect to intersection. Right?
>> Yes.
>> In multiplications. In multiplication 2 into 1= 2 or not?
>> Yes sir.
>> 5 into 1= 5. Right? 5 into 1= 5. 1 acts as multiplicative identity.
Right?
>> Yes sir.
>> In the before one empty set acts as identity.
>> Addive identity.
>> Huh. uh with respect to union. Empty set access identity with respect to union.
>> Okay sir.
>> Right. Universal set as university with respect to intersection.
Right.
>> Yes sir.
Universal set.
Please tell. 1 2 3 4 >> 1 2 3 4 5 6 7 >> 3 4 5 6 7 >> 1 2 3 4 5 6 7 >> 8 >> 1 2 3 4 5 6 7 8 9 right this one. Access access >> universal set.
>> Universal set as universal set for >> context.
Context right? Is it is it collecting all these cont?
>> Yes sir.
>> This action universal got it.
>> Yes sir.
>> Right.
What is it?
>> A intersection A is equal to what intersection itself only right?
>> Yes sir.
37.
>> Yes sir.
>> 13 57 5 >> Yeah.
>> A intersectional >> A intersection A equal to >> A.
Therefore intersection is >> very important.
Identity.
>> Identity >> intersection is important property. This is >> important >> important property right?
>> Yes.
>> Yes. What are the properties? Properties of intersection.
Properties of intersection. Number one commutative property.
What is commutative property? A intersectional >> B intersection A.
>> Right.
>> Okay.
>> Yes sir.
>> Second one. Associative property.
What is associative property?
A intersection of B intersection C is equal to >> A intersection B of intersection C >> right?
>> Yes.
>> Third one is identity property.
>> What is identity property?
A intersection is equal to intersection A= A.
Mu acts as identity.
>> Identity >> element >> element >> with respect to inter >> with respect to intersection >> identity set >> with respect to intersection.
>> Right. Access identity set with respect to intersection. Got it.
>> Yes sir. Fourth one is add important propert.
>> Yes sir.
>> Yes sir. Read these results. Read these results.
>> Communative property A intersection B is equals to B intersection A. Associative property A intersection of intersection C= A intersection B of intersection C additive property the intersection mu = mu intersection A= A set important important property intersection A= Hey, wait.
I'm not Yes, read it. Read the question.
A= = A B C B = B C D C = C E find A intersection C A and B of section A C >> union A next intersection of B union C >> A intersection B union of A intersection >> C >> right?
>> Yes sir.
>> Very simple one. Let find it. What is the number one? A >> union B intersection C.
>> First we have to find B intersection C.
Right?
>> Yes sir.
>> What is B?
>> B C D. B C D C D E C E >> C is the common element.
>> C is a common >> C is the common election is there right? Only C right.
>> Yes sir.
>> Yes sir.
>> A union of B intersection P right? Yes sir.
>> A B ABC union of >> C >> A B C >> A >> ABC Ca C means it is nothing but >> the repetition is >> repetition is not >> necessary. Yes, necessary. Union means collect all the elements of the set and collect all the elements of all the elements of this set.
>> This is nothing but not necessary. ABC right?
>> Yes sir.
>> Okay sir.
>> Number one.
What is the second one?
>> A intersection >> intersection of A C >> A union B intersection A C. First what we have to find >> a union b we have to find what is a >> c right?
>> Yes sir.
>> Union B.
>> Yes sir. B C D >> A union B set A B C Union set B. Right.
>> Yes sir.
>> What is What about this one? A B A B B B B B B B B B B B B B B B B B B B B B C C D C D C D Yes sir.
>> Here operation is union means collect all the elements, right?
>> Yes sir.
>> Okay. This not necessary directly.
directly you can write uh >> A B C D A B >> A B C D X >> A union C is equals to A C right >> yes sir >> uh what you will get directly I'm writing >> A B C E C E >> Right. Repetition is not necessary. A B C is right.
>> Yes.
>> Next intersection intersection of >> A union B intersection of union C.
>> A union Bal A B C D E.
>> Right. A B Circ from one to same or not?
>> Yes sir.
>> From one A union B inter is ABC, right?
>> Yes sir.
>> From two also it is ABC right?
>> Yes sir. From 1 and two we conclude that we >> intersectional >> A union B intersection A >> A union C >> right?
>> Yes sir. This property is called as >> distributive property of union.
>> Distributive.
>> Distributive property of union over intersection.
>> Union over inter. Distributive property of union >> over >> over intersection >> over >> intersection >> intersection >> distributive property of union >> over intersection right this is called as distributive property right >> yes sir sir >> in numbers also we have 2 * of 3 + 5 how to write we write it as 2 * 3 + 2 * >> 5 sir Yes sir.
>> 2 * 3 + 5. We can write it as 2 * 3.
>> 2 * 3 + 2 * >> right in algebra also we do x * of y + how to write x into y >> x * of y + x * x * >> right?
>> Yes.
>> This property is called as distributive property of distributive property over addition.
>> Yeah.
This property is called as multip distributive property of multiplication over >> over addition property.
Distributive property of union over >> over intersection >> intersection.
>> Okay.
>> Right.
>> Yes.
>> Yes sir.
>> Got it.
>> Yes sir.
>> First time and second over. Third one is what?
Intersection intersection B union A intersection C.
>> First third one we have to prove >> intersection of B union C. Yes.
>> What do we have to find first?
>> C.
What is set B?
>> A B C D.
>> No. What is B? Set. Check. B C D.
B set C. C E. Right.
3 CD C Dun C Ess C D E Right.
Yes sir. Yes sir.
>> Next. A intersection of B union say A B C intersection intersection B C D E right >> sir B sir.
>> What are the common elements?
>> B operation intersection right?
>> Yes sir. Since intersection is there, you take only common elements, right?
>> Common elements. Yes, sir.
>> BC >> BC right?
>> Yes sir. Yes sir.
>> Is it clear?
>> Yes sir.
>> Very simple. Very simple. This one is equation number three.
>> Yes sir.
>> Which one is what? A intersection B.
>> A intersection B.
>> A intersection B union A intersection C.
>> Right.
First what we have to find >> A intersection B intersection B >> A intersection B right >> yes B A B A B C >> intersection intersection B >> B C D B B B B B B B B B B B B B B B B B B B B C D B C D B C D What are the elements? BC B B C Yes sir.
A union C A inter >> A intersection A intersection C A B C >> A B C >> A B C >> Inter Cir.
Yes sir.
>> What are the common elements? C >> only right.
>> Yes sir.
>> Yes sir.
>> Right. Yes sir. Intersection B >> A intersection >> intersection B union intersection C= >> is equals to C B C >> Union C is equals to B C B C >> Yes. Number four. Three and four are same.
>> Yes sir.
>> What is three? A intersection intersection B union A intersection C is equal to B C.
>> Yes sir.
>> Both of them are same from >> sir. We conclude that.
A intersection of B union C is equal to >> A intersection of B union C.
>> A intersection >> C.
Yeah. Yes sir.
>> This is called as what? This property is known as >> distributive property. Distributive property.
>> This intersection over union.
This property >> property >> called as >> known as >> called known as distributive property of >> union >> intersection over add over union >> distributive property of union >> inter union over >> intersection over >> of intersection over union.
Got it.
Yes sir.
>> Distributive property of intersection over union. Right.
>> Yes sir. Yes sir.
>> This is sir.
These are the properties. Right.
>> Yes sir.
>> Therefore distributive properties.
What is the first one?
A union of B intersection C.
>> Yes sir. A intersection of >> A intersection A intersection U >> A intersection B of union of A intersection CB.
of >> intersection >> intersection A union C right >> yes sir yes sir >> second one is >> A intersection >> A intersection >> B union B union C is equals to A intersection B union A intersection C >> right >> yes sir this is called distributive properties right?
>> Yes sir. Yes sir.
>> You are you are perfect in line and intersection right?
>> Yes sir sir.
>> One minute.
>> Yes sir.
>> How many members understood this union and intersection concepts? Please raise your hand.
Very good. Many many students got it right.
>> Very nice.
Let move for other concept.
>> Yes sir.
Right.
difference of two threads.
>> Okay.
>> What is the next concept?
difference of two sets.
If we are any two sets then different set That different set is denoted with a minus b.
And the set of elements in but not in the definition. Ready?
If a and b are two sets then different set of elements in present in elements present in a but not in yes elements it is a minus b is a new set right?
>> Yeah.
>> Yes.
>> Difference set we call right.
>> Yes sir.
>> How how we are differing elements present in A but not in >> but not in B.
>> Right.
>> Yes sir.
>> Yes sir. Give me one example.
Let's read the question.
A = A B C D = B E F >> A minus B >> A minus B uh B minus C >> B minus A.
>> Yes. A - B C A B C D C F.
>> Yeah.
>> What is the A minus B set present in A but not in B?
>> Present in B.
element and >> B and D present in both or not?
>> Yes sir. Yes sir.
>> Present in A but not in B and M.
>> A and C A and C that's only present in A but not in only right. Yes sir.
Right.
Choose that one. Bi is it in B or B? It is also in B or not.
>> Yes sir.
>> Yes sir.
>> You leave it. You don't take that B. C present in A. But is it in B?
>> In B >> but not in B.
>> But not in B. That you can select C. But D. A and B and right.
>> Yes sir.
The elements only present in A but not in B.
>> Elements cancelation common elements cancel elements they are a minus right?
>> Yes sir. Yes sir. Yes sir. Yes sir.
>> B minus A means first write B.
>> Yes sir. B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D E E F B D E F E Finus A D >> elements, right? B elements >> elements common elements, right? EU s these two are equal.
>> No sir.
>> Is it A minus B and B minus A are same?
>> No sir. No sir. No sir. Earier A union B and B union are same. A intersection B and B intersection A are same. But is it A minus B and B minus A are same? No siral.
What do we conclude?
A not= minus a.
>> Therefore, difference of sets not satisfies a communive property. Right?
>> Yes, sir.
>> Yes, sir.
>> Difference of sets >> not satisfy commutative property.
>> Not satisfies >> commitive property.
>> Commutative property.
Right. Got it.
Yes sir.
>> Yes sir. That is difference of two sets.
Is it clear?
>> Yes sir. Yes sir.
Directly, what is P minus Q?
>> 1 2 3 1 2 3 4 1 2 3 5 >> Direct answer 1.
No problem. 1 2 3 5 rightus >> 2 3 4 5 >> 2 3 4 5 7 >> is equals cancel 1 >> 5 right >> yes sir >> what is Q >> - r 4a 7 >> sir 4a 7 >> 2a 3a 4 >> 3a 4a 7 - >> that's 1a 2 3 9 10 1 2 3 2 3 9 2 >> Right.
>> Yes. Yes sir.
>> 2 3 = 2a 7.
>> This is nothing but 4a 7.
>> Yes, sir.
>> Is it clear? Yes sir. This is this is the what is RUS >> 1 2 3 >> R positive right or 2 3 9 10 >> Okay sir 2 3a 2 9 10 9 10 >> 10 1 2 3 1 2 3 cancel 9 10 9 N >> right.
>> Yes sir.
>> Yes sir.
>> That is R minus P right?
>> Yes sir. Yes sir.
>> This is M. What is difference of two sets?
>> Yes sir. Yes sir.
>> It is not associative right?
>> Yeah.
>> Yes sir.
Okay. Okay.
You like that?
It's not working.
>> Okay. Say example.
>> Okay.
Read the question.
A = >> 1 2a 3 B = 1A 2A 3 B = 2 3A 2 3 3A 7 C = 3A 5A 6A 7 A - C A B of union of A - C A intersection section A - Intersection of a minus a minus c.
>> Right?
>> Yes sir.
>> How to find the first one? How to find the first one?
>> We have to find we should c right?
>> Yes sir.
>> Yes sir.
>> Then you should find a minus b union c.
Right?
>> Yes sir.
>> Then how to find second one?
So first we have first we should find a minus c then we should >> right second one is over third one how to find third one >> first we should find B intersection C next then you find a minus of B intersection C >> right how to find a minus B and A minus C. Then we should find AUS B of >> intersection of A minus C.
>> Correct.
>> Okay. Can you do this one? Homework.
This one.
>> Okay sir.
>> Yes sir.
>> This one is homework. You try it >> and Okay sir. Write the conclusion.
>> Okay sir. Okay sir.
>> What is your conclusion? After finding the finding these values you write the conclusion, right?
>> Okay sir. Okay sir. Which which are equal? Which are which are equal? You can write it. Okay.
>> Okay. Okay.
>> Right. This is homework.
>> Okay. Bye. Not down note down all these notes clearly.
>> Okay, sir. Okay, sir.
>> Not down all these notes very clearly.
Okay. Bye. This is the one.
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