Question

For $a,b\in R^{+},$ match the following quadratic equations with their corresponding discriminant.

• A. $-23$
• B. $4$
• C. $-24$
• D. $-8$

Answer 1

For a quadratic equation of the form $a{x}^2+bx+c=0,a\ne 0$,
Discriminant is given by $D=b^2-4ac$

(i)$3x^2+2x=0$
$\Rightarrow D=2^2-4\left(3\right)\left(0\right)=4$

(ii)$x^2+2x+3=0$
$\Rightarrow D=2^2-4\left(1\right)\left(3\right)=-8$

(iii)$2x^2+3=0$
$\Rightarrow D=0^2-4\left(2\right)\left(3\right)=-24$

(iv)$2x^2+x+3=0$
$\Rightarrow D=1^2-4\left(2\right)\left(3\right)=-23$