Question

rationalise √2+1/√2-1​

Answer 1

To rationalise we have to change the sign of the denominator and then multiply it with both numerator and denominator.

Then apply the identity depending on the sign of numerator...

In numerator , it may be either :-

• (a + b)² = a² + b² + 2ab

or

• (a - b)² = a² + b² - 2ab

But in the denominator , it is always :-

• (a + b) (a - b) = a² - b²