SOLUTION: how and when would you use the "discriminant"?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: how and when would you use the "discriminant"?      Log On


   

Question 172073: how and when would you use the "discriminant"?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
The discriminant is the part of the quadratic formula that is under the radical sign.

Quadratic formula: x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

So the discriminant is: DELTA+=+b%5E2-4ac

Use the discriminant to determine the character of the roots of a quadratic equation.

if DELTA=0 there is one real number root with a multiplicity of 2.

if DELTA%3E0 there are two real number roots.

if DELTA%3C0 there is a conjugate pair of complex roots of the form a%2B-bi