Question

What is the discriminant of the quadratic equation 2x² - x - 3=0?
A. -25
B. 25
C. -23
D. 23

Answer 1

The given quadratic equation is

$2 {x}^{2} - x - 3 = 0$

comparing with

${ax}^{2} + bx + c = 0$

We get ,

$a = 2 \\ b = - 1 \\ c = - 3$

formula :

$D = {b}^{2} - 4ac \\ \\ D = {( - 1)}^{2} - 4 \times 2 \times ( - 3) \\ \\ D = 1 - ( - 24) \\ \\D = 1 + 24 \\ \\D = 25.$

Discriminant of given quadratic equation is 25 .

option (B) 25 ✔