Question

What is the value of the discriminant for the quadratic equation 0 = x + 2 + x2?

Answer 1

Answer:- The value of discriminant= -7

Explanation:-

Given quadratic equation :- $0=x+2+x^2$ which can be rewritten as $x^2+x+2=0$

On  comparing this with the standard quadratic equation$ax^2+bx+c=0$, we have a =1 ,b=1 and c=0

We know that, Discriminant $D=b^2-4ac$

$\\\\\Rightarrow\ D=1^2-4(1)(2)=1-8\\\\\Rightarrow\ D=-7$

Thus for the given quadratic equation the value of discriminant= -7

Answer 2

The discriminant of a quadratic expression $ax^2+bx+c$, where a in not 0, is the expression 
                                       $D=b^2-4ac$.  

Thus, we compare $x^2+x+2$ to $ax^2+bx+c$ and see that 

a=1, b=1, c=2.

Substituting these values in  $D=b^2-4ac$, we have:

                               $D=(1)^2-4\cdot1\cdot2=1-8=-7$.


Answer: -7