surd
TODAY...Definition of a Surd: The n th root of a number a is denoted as n √a (also as a1/n ) Let a be a rational number and n a positive integer. Then n √a is called a Surd if it, i.e. n √a is an irrational number. n√a is spoken as “n th root of a” n th root of a number a is a surd, if it is an irrational number. Examples of Surds: 2 √2 or just √2 is a surd. 3√9, 3√16, 4√25, 5√100 are all numbers whose given roots are not rational numbers. They are therefore Surds .