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Ordered Pairs In A Cartesian Plane

The ordered pairs of a coordinate system have elements of the set Cartesian product. Ordered pairs in the Cartesian plane differ in dimensions with the sets.

A set is a collection of distinct characters or elements enclosed within curly brackets and separated by commas. The ordered pair of a coordinate system contains elements that are orderly within the braces. It is the x and y coordinates written within the brackets as (x,y). The concept of the Cartesian product was first introduced by Rene Descartes in 1637. It portrays the product of the ordered elements of two sets. The Cartesian product is not restricted to only two ordered sets. According to the number of sets involved in the Cartesian product, the dimensions of the plane differ. 

Ordered Pairs

  • Interchanging the order of the elements changes the whole meaning of the set. 

  • The x-coordinate should be in the place of x(abscissa) only. 

  • So is the rule for the y-coordinate, too. The ‘y’-coordinate should be in the place of the y-axis(ordinate) value.

  • Ordered pairs don’t mean that the pairs in the sets are equal to each other.

Ordered pair example

On solving an algebraic equation, the obtained values of 

  • x are 1 and 3 

  • y are 2 and 4

When they are written as a set, they are ordered as 

  • A = (1,2) 

  • B = (3,4)

A Cartesian plane

  • The Cartesian plane is, generally, a two-dimensional plane consisting of the x and y axes. 

  • The coordinates of the Cartesian coordinate plane are a set of ordered pairs of a coordinate system. 

  • The ordered sets in the Cartesian plane are plotted in the x and y axes in an orderly manner. 

  • The order of the Cartesian coordinates is never altered.

A one-dimensional Cartesian plane

  • A one-dimensional Cartesian plane shows a straight line drawn like a number line.

  • It has real numbers on the line, giving the distance of a point from the O.

A two-dimensional Cartesian plane

  • The coordinates are obtained from the Cartesian product of two ordered sets in the Cartesian plane.

  • A two-dimensional Cartesian plane is a graph drawn with an ordered pair of a coordinate system.

  • The ordered pair has two values of x-coordinate and y-coordinate, forming a 2D graph.

  • The graph has two perpendicular lines of x and y axes that intersect each other at 0.

  • The x-coordinate is called abscissa, and the ‘y’-coordinate is the ordinate.

A three-dimensional Cartesian plane

  • The coordinates are the Cartesian product of three ordered sets in the Cartesian plane.

  • It gives a three-dimensional graph in the Cartesian coordinate system.

  • The ordered triplets have three values for the x, y, and z coordinates, forming a 3D graph.

  • The graph has three perpendicular lines intersecting each other at right angles in the point of origin O.

Cartesian product

The Cartesian product of ordered sets is denoted as a multiplication function of the two given sets. For example, considering the ordered sets X and Y, the Cartesian product is denoted as X x Y.

Cartesian product example

Considering the examples given in the above topic ‘Ordered pair example’, the ordered pair of sets are

Set A = {1,2} 

Set B = {3,4}

Their Cartesian product is 

A x B = {(1,3)(2,4)(2,3)(1,4)}

Where,(1,2) ∈ A 

(3,4) ∈ B

Their orders cannot be changed because changing the order of the ordered sets makes the sum faulty.

Solved examples

Here are some solved examples for a better understanding of the ordered sets in a Cartesian plane. 

  1. Consider a set where A = {a,b} and B = {y,z}. Write the Cartesian product of the ordered pair.

A = {a,b} 

B = {y,z}

The Cartesian product is denoted as A x B.

A x B = {(a,y)(b,z)(a,z)(b,y)}

  1. Consider a set Y = {white,black} and Z = {chalk,pencil}. Write the Cartesian product of the given ordered sets.

Y = {white,black} 

Z = {chalk,pencil}

The Cartesian product is denoted as X x Y.

X x Y = {(white,chalk)(white,pencil)(black,chalk)(black,pencil)}

  1. Consider sets A and B. The Cartesian product of set A x B has 50 elements, and set A has ten elements. How many elements are present in set B?

The product of the number of elements in the given two sets gives the total number of elements in the set Cartesian product.

Number of elements in A x B = 50

Number of elements in A = 10

B = (A x B) / A

B = 50 / 10

B = 5

There are 5 elements in the ordered set B.

  1. If the Cartesian product set of A x B is {(1,5),(9,5)}. Find the ordered sets A and B.

The Cartesian product set has the elements of the individual sets clubbed in an ordered manner.

A x B = {(1,5),(9,5)}

A = {1,9}

B = {5}

Conclusion

In the ordered pairs of a coordinate system, their order cannot be interchanged. The abscissa lies in the x-axis, and the ordinate lies in the y-axis. Their set product is given by the Cartesian product. The pairs of the set lie as the ordered sets in the Cartesian plane. Based on the sets considered for the Cartesian product, the Cartesian plane differs as one or two or three or multidimensional. When two ordered pairs are considered, the Cartesian plane is two-dimensional. When three ordered triplets are considered, the Cartesian plane is three-dimensional. You have learnt about ordered sets and ordered sets in Cartesian planes in this article.

 
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Frequently asked questions

Get answers to the most common queries related to the CBSE Class 11 Examination Preparation.

What is a set?

Ans : A set is a collection of distinct...Read full

Consider the set A = {a,x} and B = {y,z}. What is the Cartesian product of the ordered pairs?

Ans : Given that,  A = {a,x}  ...Read full

The Cartesian product is calculated for two sets, A and B. The total number of elements in the set Cartesian product is 10, and the number of elements in set A is 2. What is the total number of elements in set B?

Ans : Given that,  A x B = 10 ...Read full

What is the first element in an ordered pair called?

Ans : The first element in an ordered pair is called the first coordinate. To use ordered pairs to represent a funct...Read full