C1 Topic 2: Algebra
Simplifying surds
A surd is a number written in a form that includes a square root. For example \sqrt 3 , 1+\sqrt 2 and 7\sqrt 5 are all examples of surds. A surd is a useful way of giving a value in a precise, or exact, form where there is no need to be concerned with accuracy or decimal places.

Summary When simplifying surds, look for factors that are square numbers themselves. Remember that to complete the proof a result involving surds you must use of factors. To evaluate the square root on a calculator is unacceptable. Calculators are not allowed in the C1 exam anyway. Remember the all-important rule: \sqrt{ab} = \sqrt{a}\sqrt{b} This page uses jsMath. Note that you can get a better display of the maths by downloading special TeX fonts from jsMath. In the meantime, we will do the best we can with the fonts you have, but it may not be pretty and some equations may not be rendered correctly.