If the root of rational number is an irrational number then the resulting number is called surds .This video gives the information of rationalising factor.
Go to Surds Note page
Surds - the basics
Surds and Operations
What is a Rationalising Factor(Conjugate)?
Rationalisation Of A Surd / Radical : A Basic Introduction With Examples - Maths Arithmetic
Signup using your facebook account
Login with your Kullabs account