Question

Find the square root of a number $1764$ by the prime factorisation method.

Answer 1

By using prime factorisation method:

$1764=2\times 2\times 3\times 3\times 7\times 7=2^2\times 3^2\times 7^2$

Taking square root, we have
$\sqrt{1764}=\sqrt{2^2\times 3^2\times 7^2}$

$=2\times 3\times 7$
$=42$