SOLUTION: here is the directions: FIND THE DISCRIMINANT AND USE IT TO DETERMINE THE NUMBER OF REAL SOLUTIONS OF THE EQUATION........I have no idea how to work these problems...here is one o

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: here is the directions: FIND THE DISCRIMINANT AND USE IT TO DETERMINE THE NUMBER OF REAL SOLUTIONS OF THE EQUATION........I have no idea how to work these problems...here is one o      Log On


   

Question 20514: here is the directions: FIND THE DISCRIMINANT AND USE IT TO DETERMINE THE NUMBER OF REAL SOLUTIONS OF THE EQUATION........I have no idea how to work these problems...here is one of them.
x^2-2x-3=0
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
The discriminant is the part of the quadratic formula under the radical.
The quadratic formula is: x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a
The discriminant is: b%5E2-4ac
The value of the discriminant can tell you something about the solutions to a quadratic equation, without actually solving the equation.
If the discriminant is positive, the quadratic equation has two real roots.
If the discriminant is negative, the quadratic equation has two complex (a+bi) roots.
If the discriminant is zero, the quadratic equation has one real root (a double root).
Applying this to your quadratic equation x%5E2-2x-3=0, the discriminant is: %28-2%29%5E2-4%281%29%28-3%29 = 16
The value of the discriminant is positive, therefore, the solution has two real roots.