Question

Solve the quadratic equation $x^2-4x+2=0$ by formula method.

Answer 1

$x^2-4x+2=0$
$a=1,b=-4,c=2$
$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
$x=\frac{-(-4)\pm \sqrt{(-4{)}^2-4(1\left)\right(2)}}{2\left(1\right)}$
$x=\frac{4\pm \sqrt{16-8}}{2}$
$x=\frac{4\pm \sqrt{8}}{2}$
$x=\frac{4\pm 2\sqrt{2}}{2}$
$=\frac{2(2\pm \sqrt{2})}{2}$
$x=2\pm \sqrt{2}$.