How do you rationale the denominator?

Answer 1

Depends on the situation. You usually have to multiply numerator and denominator by some number or expression.

Examples:

1 / square root of 2

Here, you have to multiply numerator and denominator by the square root of 2.

1 / (square root of 2 + square root of 3)

Here, you have to multiply numerator and denominator by (square root of 2 - square root of 3).