Union And Intersection Formula
The empty set is an identity element for the operation of union.
Union and intersection formula. If this is the case then we can calculate the probability of the intersection of a given b by simply multiplying two other probabilities. We can define the union of a collection of sets as the set of all distinct elements that are in any of these sets. This follows from analogous facts about logical disjunction. The probability of the intersection of two events.
That is a a for any set a. We will take the common elements at once only. This example illustrates how to use the union and intersect operator borders below for illustration only in excel. The goal will be to calculate the probability of the union of these three sets or p a u b.
This version of the formula is most useful when we know the conditional probability of a given b as well as the probability of the event b. The union operator comma adds two ranges. We will extend the above ideas to the situation where we have three sets which we will denote a b and c. Since sets with unions and intersections form a boolean algebra intersection distributes over union.
The intersection of sets a and b denoted by a b is x x a x b disjoint of sets. The union of two sets a and b is the set of all the elements present in a or b or both. An element is in the union if it belongs to at least one of the sets. This is the set of all distinct elements that are in both a a a and b b b.
In order to perform basic probability calculations we need to review the ideas from set theory related to the set operations of union intersection and complement. The intersection of 2 sets a a a and b b b is denoted by a b a cap b a b. We will not assume anything more than this so there is the possibility that the sets have a non empty intersection. A useful way to remember the symbol is i cap tersection.
Use of formula. Similarly union is commutative so the sets can be written in any order. The union of two or more sets is the set that contains all the elements of each of the sets. To solve the practical problems related to union and intersection first we need to summarize the meaning of union intersection and difference of sets.
If a and b are sets we define their union as the set consisting of all elements that belong to a or b and denoted it by a u b is x x a or x b intersection of sets. The sum function reduces to sum c4 d8 sum d7 e11 20.