LEARN MATH STEP BY STEP THROUGH VERY EASY PROCESS

RELATION & MAPPING - RELATION IN ROSTER FORM

**Express the following
relations in the roster form –**

__Example.1)__

**The matching pairs are (1, 1), (27, 3), (64, 4), (125, 5)**

**So, the relation R = {(1, 1), (27, 3), (64, 4), (125, 5)} is
from the set,**

**A = {1, 27, 64, 125} to the set B = {4, 1, 5, 3}, Also in
each pair the first element “is the cube of” the second elements.**

**We write – 1 R 1, 27 R 3, 64 R 4, 125 R 5**

**And, R = {(a, b) : a
Є A, b Є B and a = bᶟ}**

**Example.2)**

**The matching pairs are (Rome, Italy), (Tehran, Iran), (Beijing, Chaina), (Lisbon, Portugal)**

**So, the relationis R = {(Rome, Italy), (Tehran, Iran), (
Beijing, Chaina), (Lisbon, Portugal)},**

**From the set A = {Rome, Tehran, Beijing, Lisbon} and B = {Chaina, Italy, Portugal, Iran}**

**And, it can be described as “ is the capital of ”**

**We can also write Rome R Italy, Tehran
R Iran, Beijing
R China, Lisbon
R Portugal**

**And R = {(a, b) : a Є
A, b Є B and a is the capital of b }**