SOLUTION: What is the discriminant and how do you find it if you are given a quadratic equation? For instance, if you have -x² + 12 + 20 = 0, what would the discriminant be? How many solut

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: What is the discriminant and how do you find it if you are given a quadratic equation? For instance, if you have -x² + 12 + 20 = 0, what would the discriminant be? How many solut      Log On


   

Question 475756: What is the discriminant and how do you find it if you are given a quadratic equation? For instance, if you have -x² + 12 + 20 = 0, what would the discriminant be? How many solutions would this equation have?

Found 2 solutions by rfer, Gogonati:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
a=-1, b=12, c=20
the discriminant is the part under the radical sign.
(12^2)-4*-1*20=80+144=224
sqrt224=14.97
x=-1.5
x=13.5
two solutions

Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
The standard form of the quadratic equation is ax%5E2%2Bbx%2Bc=0, where a, b, c
are real numbers and a is different from zero. The discriminant of the quadratic
equation is the expression b%5E2-4ac If b%5E2-4ac%3E0 the quadratic
equation has two real roots. If b%5E2-4ac=0 the quadratic equation has one
real root, and if b%5E2-4ac%3C0 the quadratic equation has not real solution.
Example:For the equation -x%5E2%2B12x%2B20=0 the discriminant is:
12^2-4(-1)*20=144+80=224>0, this equation has two real roots.