Question

Question 2 (iv)
Find the roots of the quadratic equations given in Q.1 above by applying the quadratic formula.
(iv) $2x^2+x+4=0$

Answer 1

(iv) $2x^2+x+4=0$
On comparing this equation with $a{x}^2+bx+c=0$, we get
a = 2, b = 1 and c = 4
By using quadratic formula, we get
$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
$\Rightarrow$$x=\frac{-1\pm \sqrt{(1{)}^2-4\times 2\times 4}}{2\times 2}$
$\Rightarrow$ $x=\frac{-1\pm \sqrt{1-32}}{4}$
$\Rightarrow$ $x=\frac{-1\pm \sqrt{-31}}{4}$
The square of a number can never be negative.
$\therefore$ There is no real solution for this equation.