Question

find the discrimant of 2x2 + 10x + 21 = 0.

Answer 1

Equation:

$2 {x}^{2} + 10x + 21 = 0$


Here a =2

b = 10

c=21

$\bf{Discriminant }$(D) =${ b}^{2} -4ac$

$= {10}^{2} - 4 \times 2 \times 21$


$= 100 - 168$


=-68

So, discriminant of the equation =-68 .

Answer 2

D=b2–4ac
=(10)²–4×2×21
=100–168
=–68
the sign is negative
so no real roots