Describe the following sets in Roster form :
(i) {x : x is a letter before e in the English alphabet}.
(ii) {x ϵ N:x2<25}
(iii) {x ϵ N: x is a prime number, 10 < x < 20}.
Describe the following sets in Roster form :
(i) {x : x is a letter before e in the English alphabet}.
(ii) {x ϵ N:x2<25}
(iii) {x ϵ N: x is a prime number, 10 < x < 20}.
(i) In Roster form, we describe a set by listing its elements, separated by commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on '.
The above set in Roster form can be written as {a, b, c, d}. Since the letters a,b,c and d precedes e in the english alphabet.
(ii) In Roster form, we describe a set by listing its elements, separated commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on'.
1 ϵ N∵12=1<252 ϵ N∵22=4<253 ϵ N∵32=9<254 ϵ N∵42=16<25
Hence, the above set can be written as {1,2,3,4}
(iii) In Roster form, we describe a set by lisiting its elements, separated by commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on '.
We note that a < x < b means that x is more than a but less than b.
The prime numbers which are more than 10 fact less than 20 are 11, 13, 17 and 19. Hence the above set can be written as {11, 13, 17, 19}
(i) In Roster form, we describe a set by listing its elements, separated by commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on '.
The above set in Roster form can be written as {a, b, c, d}. Since the letters a,b,c and d precedes e in the english alphabet.
(ii) In Roster form, we describe a set by listing its elements, separated commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on'.
1 ϵ N∵12=1<252 ϵ N∵22=4<253 ϵ N∵32=9<254 ϵ N∵42=16<25
Hence, the above set can be written as {1,2,3,4}
(iii) In Roster form, we describe a set by lisiting its elements, separated by commas and the elements are written within braces { }. If a set has infinitely many elements, then comma is followed by ....., where the dots stand for 'and so on '.
We note that a < x < b means that x is more than a but less than b.
The prime numbers which are more than 10 fact less than 20 are 11, 13, 17 and 19. Hence the above set can be written as {11, 13, 17, 19}
