Rationalise the denominator 10/root 2

So,

A denominator is rationalized when there are no irrational or imaginary numbers in it.  Since the square root of 2 is irrational, we just need to multiply the fraction by the square root of 2 over the square root of 2.



Multiply the fraction by the square root of 2 over the square root of 2.


Simplify.




The denominator is now 1, which is a rational number.