Examples

Chapter 1 Class 12 Relation and Functions
Serial order wise

### Transcript

Question 21 Show that zero is the identity for addition on R and 1 is the identity for multiplication on R. But there is no identity element for the operations : R R R and : R R R . Addition e is the identity of * if a * e = e * a = a i.e. a + e = e + a = a This is possible if e = 0 Since a + 0 = 0 + a = a a R 0 is the identity element for addition on R Multiplication e is the identity of * if a * e = e * a = a i.e. a e = e a = a This is possible if e = 1 Since a 1 = 1 a = a a R 1 is the identity element for multiplication on R Subtraction e is the identity of * if a * e = e * a = a i.e. a e = e a = a There is no possible value of e where a e = e a So, subtraction has no identity element in R Division e is the identity of * if a * e = e * a = a i.e. = = a There is no possible value of e where = = a So, division has no identity element in R*

#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.