Question

Find roots of $2x^2+x-4=0$ using formula.

Answer 1

$2x^2+x-4=0$

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Here $a=2,b=1,c=-4$

$x=\frac{-1\pm \sqrt{1^2-4\left(2\right)(-4)}}{2\times 2}$

$=\frac{-1\pm \sqrt{1+32}}{4}=\frac{-1\pm \sqrt{33}}{4}$

Hence the roots are $\frac{-1+\sqrt{33}}{4}$ and $\frac{-1-\sqrt{33}}{4}$