Question

what is a surd ? give an example

Answer 1

If  we  can't  simplify  a  number  to  remove   a  square  root, cube  root  etc.  then  it  is  a  surd.
 eg;    Square  root  of  2    cannot  be  simplified  further  hence  it  is  a  surd.

Answer 2

An irrational root of a rational number is called a surd.
or
When we can't simplify a number to remove a square root (or cube root etc) then it is a surd
examples--->
1. √2 (square root of 2) can't be simplified further so it is a surd
    √2 decimal form is 1.4142135...(etc) thus its a surd
2. √3 (square root of 3) can't be simplified further so it is a surd
    √3 decimal form is 1.7320508...(etc) thus its a surd
3.  3√11 is a surd
4.  5√3  is a surd

[there are 2 types of surds>>>> like surds and unlike surds ]

hope my answer helped you......