How do you find the discriminant #x^2+x-12#?

1 Answer
May 3, 2016

Answer:

49

Explanation:

Given a quadratic equation in standard form #ax^2 +bx+c=0 #

Then the discriminant #color(red)(|bar(ul(color(white)(a/a)color(black)((Delta)=b^2-4ac)color(white)(a/a)|))) #

The value of the discriminant gives information on the #color(blue)" nature of the roots "#

#• b^2-4ac > 0 " roots are real and irrational "#

However if #b^2-4ac " is a square , roots are real and rational"#

#• b^2-4ac=0 " roots are real and equal "#

#• b^2-4ac < " roots are not real "#

For the given function here #x^2+x-12 , a=1,b=1,c=-12#

#rArr b^2-4ac=1^2-(4xx1xx-12)=49#

Since #b^2-4ac > 0 " and a square , roots will be real and rational"#