Question

square root of 9-4√5​

Answer 1

$\huge{\texttt{SOLUTION:-}}$

$\sqrt{9 - 4 \sqrt{5} }$

$\sqrt{9 - 2 \sqrt{20} }$

$\sqrt{5 + 4 - 2 \sqrt{5 \times 4} }$

$\sqrt{5} - \sqrt{4}$

$\sqrt{5} - 2$

$\textsf{\underline{\underline{EXPLANATION:-}}}$

An easy trick to find square roots of this type problem is just finding the roots of the terms which are given inside the roots and simplifying them till the end.

A surd is a form of irrational number

If n is positive integer and a is rational number and is not the nth power of any rational number , then n root a is called a surd

A surd is a square root which cannot be reduced to a whole number

A surd is a number that cannot be simplified to remove a square root

If two surds are different multiples of same surds then , the surds are similar and if they are not multiples , they are dissimilar surds

By knowing the basic principles of surds , we can solve any type of problem easily