# Surds

Author:
pirsquared

## Key Facts

You need to know the following:
• A square root such as is a surd. (But not, eg. )
• Surds multiply and divide as normal:  and
• Surds simplify by decomposing them into a product with a square number, and applying the root to that square - eg.

## Test Yourself: Simplifying Surds

• You can rationalise surds of the form  by multiplying by  - this keeps the fraction the same value, but 'eliminates' the surd from the bottom: