Question

Question 1 Which of the following relations are functions? Give reasons. If it is a function, determine its domain and range.

(i) {(2, 1), (5, 1), (8, 1), (11, 1), (14, 1), (17, 1)}

(ii) {(2, 1), (4, 2), (6, 3), (8, 4), (10, 5), (12, 6), (14, 7)}

(iii) {(1, 3), (1, 5), (2, 5)}

Class XI - Relations and Functions Page 44

Answer 1

refer to the attachment

Answer 2

Here,

(i) and (ii) are functions. A relations is called function if every first element has one and only image. In the (iii) relation we can see that element '1' has two images, 3 and 5. {(1, 3), (1, 5)}

Domain is the set of first element of a relation, range is the set of second element of the relation.

Hence,

i) Domain : {2, 5, 8, 11, 14, 17}

Range : {1}

ii) Domain : {2, 4, 6, 8, 10, 12, 14}

Range : {1, 2, 3, 4, 5, 6, 7}