Question

Find the roots of each of the following quadratic equations by the method of completing the sqaures:
$x^2-6x+4=0$

• A. $9\pm \sqrt{8}$
• B. $6\pm \sqrt{7}$
• C. $3\pm \sqrt{5}$
• D. $1\pm \sqrt{1}1$

Answer 1

Answer: (C)

$3\pm \sqrt{5}$

Given, $x^2-6x+4=0$
$\Rightarrow (x-3{)}^2-9+4=0$
$\Rightarrow (x-3{)}^2=5$
$\Rightarrow x-3=\pm \sqrt{5}$
$\Rightarrow x=3\pm \sqrt{5}$