512,678 views
34 votes
34 votes
What is the discrimant of x^2 +x-2=0

User Justinf
by
2.7k points

1 Answer

15 votes
15 votes

Answer:

Discriminant = 9.

Explanation:

Discriminant


\boxed{b^2-4ac}\quad\textsf{when}\;ax^2+bx+c=0


\textsf{when $b^2-4ac > 0 \implies$ two real roots}.


\textsf{when $b^2-4ac=0 \implies$ one real root}.


\textsf{when $b^2-4ac < 0 \implies$ no real roots}.

Given function:


x^2+x-2=0

Therefore:

  • a = 1
  • b = 1
  • c = -2

Substitute the values of a, b and c into the discriminant formula:


\begin{aligned} \implies b^2=4ac&amp;=(1)^2-4(1)(-2)\\&amp;=1-4(-2)\\&amp;=1+8\\&amp;=9\end{aligned}

Therefore, the discriminant of the given function is 9.

As the discriminant is greater than zero, this implies that there are two real roots.

User Harke
by
2.4k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.