Question

Question 1 (v)

Find the roots of the quadratic equations by using the quadratic formula in the following question.

$x^2+2\sqrt{2}x-6=0$

Answer 1

Given equation is $x^2+2\sqrt{2}x-6=0$
on comparing with $a{x}^2$ + bx + c = 0, we have
a = 1, b = 2$\sqrt{2}$ and c = -6
By quadratic formula, $x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
$=\frac{-2\sqrt{2}\pm \sqrt{8+24}}{2}=\frac{-2\sqrt{2}\pm 4\sqrt{2}}{2}$
$=-\sqrt{2}+2\sqrt{2},-\sqrt{2}-2\sqrt{2}=\sqrt{2},-3\sqrt{2}$
So, $-3\sqrt{2}and\sqrt{2}$ are the roots of the given equation