We do not leave an irrational number in the denominator.

So, we rationalise the denominator.  Let us look at some examples

  1. Rationalise 1/√2
  2. Rationalise 1/2 +√3
  1. Chapter 1 Class 9 Number Systems
  2. Concept wise


Some Identities (โˆš๐‘Ž)^2=๐‘Ž โˆš(๐‘Ž^2 )=๐‘Ž โˆš๐‘Ž๐‘=โˆš๐‘Ž ร—โˆš๐‘ โˆš(๐‘Ž/๐‘)=โˆš๐‘Ž/โˆš๐‘ (โˆš๐‘Žโˆ’โˆš๐‘)(โˆš๐‘Ž+โˆš๐‘)=๐‘Žโˆ’๐‘ (๐‘Žโˆ’โˆš๐‘)(๐‘Ž+โˆš๐‘)=๐‘Ž^2โˆ’๐‘ (โˆš๐‘Ž+โˆš๐‘)^2=๐‘Ž+๐‘+2โˆš๐‘Ž๐‘ (โˆš๐‘Ž+โˆš๐‘)(โˆš๐‘+โˆš๐‘‘)=โˆš๐‘Ž๐‘+โˆš๐‘Ž๐‘‘ + โˆš๐‘๐‘ + โˆš๐‘๐‘‘

About the Author

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.