Rationalisation Method

Rationalisation Method

For expressions involving radicals, multiply by the conjugate expression.

For example:

$$\sqrt{f(x)}-\sqrt{g(x)}$$

can be rationalised using:

$$\left(\sqrt{f(x)}-\sqrt{g(x)}\right)\left(\sqrt{f(x)}+\sqrt{g(x)}\right)=f(x)-g(x)$$

Usage

- Used to remove radicals and resolve indeterminate forms such as $$\frac{0}{0}$$.