Set Relations, Subset & Subset of Real Numbers - Sets & Relations | Class 11 Applied Maths Chapter 5

Magnet Brains・2 minutes read

The text discusses sets, relations, and subsets, emphasizing the importance of understanding concepts through examples and exercises. It also covers the cardinal numbers, subsets, supersets, and power sets in set theory, highlighting their significance in mathematics.

Insights

  • Sets are considered equivalent if they have the same number of elements, known as cardinal numbers, regardless of the specific elements present in each set.
  • The power set of a set contains all possible subsets, including the set itself, with the number of subsets determined by the formula 2 to the power of the original set's elements.

Get key ideas from YouTube videos. It’s free

Recent questions

  • What are equivalent sets?

    Sets with the same number of elements.

Related videos

Summary

00:00

Understanding Sets and Relations in Mathematics

  • The session focuses on sets and relations, particularly discussing larger subsets of relations and real numbers.
  • The session is structured like a match, engaging students in an interesting topic from class 11.
  • Prior exercises on sets have been completed, emphasizing the importance of understanding concepts and practicing questions.
  • Lectures and videos are available on YouTube, the website, or through the instructor for further learning.
  • Equivalent sets are defined by having the same number of elements, termed as cardinal numbers.
  • Sets are considered equivalent if they share the same number of elements, regardless of the specific elements.
  • Equal sets are distinguished from equivalent sets, requiring every member of one set to be a member of the other set.
  • The equality of sets is contingent on the involvement of both sets' members, ensuring a balanced comparison.
  • The concept of subsets is introduced, where one set is considered a subset of another if every element of the former is also in the latter.
  • Supersets are the inverse of subsets, with one set being a superset of another if the latter is a subset of the former.

17:30

Understanding Sets: Subsets, Supersets, and Formulas

  • To determine if set A is a subset of set B, check if every element in A is also in B.
  • If there exists at least one element in A that is not in B, then A is not a subset of B.
  • An example is given with sentences to illustrate the concept of subsets and truthfulness.
  • A set is considered a superset if it contains all elements of another set.
  • The example of sets A and B with elements 2, 3, and 5 is used to explain supersets.
  • The concept of proper subsets is introduced, where a proper subset must have at least one element not in the larger set.
  • The relationship between subsets and supersets is discussed, emphasizing equality when all elements match.
  • The definition of an improper subset is explained as a set that is not a proper subset of itself.
  • The concept of an empty set as a subset of every set is clarified.
  • The formula for calculating the number of subsets in a set is provided, based on the number of elements.

35:17

"Understanding Power Sets and Universal Sets"

  • Power set is formed by taking all subjects together in one set, creating a power set of A.
  • The power set of A contains all its subjects, including the bracket that is not usually seen.
  • If a set with n=m, then the power set will have 2^m elements.
  • The universal set is the collection of all subsets, with the number of subsets determined by the number of elements.
  • The universal set is crucial in problem-solving, defining all possible elements under consideration.
  • The universal set changes based on the problem, with different examples like a child's universe evolving with age.
  • Real numbers have various subsets, including natural numbers, whole numbers, integers, rational numbers, and irrational numbers.
  • Natural numbers are subsets of whole numbers, which are subsets of integers, and so on.
  • Rational numbers are subsets of real numbers, with natural numbers being subsets of rational numbers.
  • Open intervals do not include the endpoints, while closed intervals include them, with a unique representation on the real axis.

52:36

Understanding Infinity in Set Theory

  • Brother X should be greater than 8000, even if it's ₹18 crores.
  • In finance, intervals are used to denote real numbers x where a² is infinite.
  • The set builder form for x > A is from A to infinity for real numbers.
  • Including A in the set changes the representation to include A and all values greater than A.
  • The bracket notation changes from curved to square when A is included in the set.
  • The concept of infinity is not a number but signifies an unbounded value.
  • Infinity represents the largest value without bounds, allowing for limitless expansion.
  • The symbol for infinity indicates a value that can extend indefinitely.
  • Examples of equal sets are determined by converting set forms and comparing elements.
  • The empty set is a subset of every set, showcasing its unique role in set theory.

01:08:01

Understanding Subset Relationships in Sets

  • Subset relationship between sets B and C explained
  • Elements of set B are included in set C
  • Relationship of sets A and C discussed
  • Elements of set A are included in set C
  • Comparison of elements in sets A and D
  • Clarification on the concept of subsets and elements
  • Explanation of the difference between elements and subsets
  • Clarification on creating subsets and the use of brackets
  • Explanation of subsets based on elements in sets
  • Illustration of the difference between sets A and B in roster form

01:25:15

Calculating Power Sets and Cardinal Numbers

  • To find the power set of a set, consider each element individually.
  • The power set includes subsets of the set.
  • The cardinal number of a set is the count of its elements.
  • The formula for the cardinal number of a power set is 2 to the power of the original set's elements.
  • The number of subsets in a power set is determined by the original set's elements.
  • Solving equations involving the cardinal numbers of sets can help find the values of elements.
  • The total number of subsets in a set can be calculated using the formula 2 to the power of the set's elements.
Channel avatarChannel avatarChannel avatarChannel avatarChannel avatar

Try it yourself — It’s free.