Question

Roots of the quadratic equation $4x^2+7x+2=0$, are

• A. $x=\frac{-7\pm \sqrt{11}}{8}$
• B. $x=\frac{-7\pm \sqrt{-17}}{8}$
• C. $x=\frac{-7\pm \sqrt{17}}{8}$
• D. $x=\frac{-4\pm \sqrt{17}}{8}$

Answer 1

The correct option is C $x=\frac{-7\pm \sqrt{17}}{8}$

$4x^2+7x+2=0$
Using quadratic formula,
$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
$x=\frac{-7\pm \sqrt{49-4\left(2\right)\left(4\right)}}{2\times 4}$
$x=\frac{-7\pm \sqrt{17}}{8}$