Watch this video to learn about the rules of surds. For example, \(\sqrt 4 = 2\) is not a surd. However \(\sqrt 5\) is a surd. If you use a calculator, you will see that \(\sqrt 5 = 2.236067977...\) ...

Surds are square roots which can’t be reduced to rational numbers. Some can be simplified using various rules or by rationalising the denominator. Simplifying expressions using the laws of indices ...