Question

Find the roots of following quadratic equation

$x^2+3x-2=0$

• A. $x=\frac{-3\pm \sqrt{15}}{2}$
• B. $x=\frac{-3\pm \sqrt{17}}{2}$
• C. $x=\frac{-3\pm \sqrt{19}}{2}$
• D. $x=\frac{-3\pm \sqrt{21}}{2}$

Answer 1

The correct option is B $x=\frac{-3\pm \sqrt{17}}{2}$

Gven equation is

$x^2+3x-2=0$
Using quadratic formula,
$a=1,b=3,c=-2$

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
$x=\frac{-3\pm \sqrt{9-4\left(1\right)(-2)}}{2\times 1}$
$\therefore x=\frac{-3\pm \sqrt{17}}{2}$

$\therefore$ the roots of the given equation are $\frac{-3\pm \sqrt{17}}{2}$