SOLUTION: In the equation ax^2+bx+c=0, the value of b^2-4ac is called the _______ of the quadratic equation. What does this value tell you about the real roots of the equation.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: In the equation ax^2+bx+c=0, the value of b^2-4ac is called the _______ of the quadratic equation. What does this value tell you about the real roots of the equation.      Log On


   



Question 171214: In the equation ax^2+bx+c=0, the value of b^2-4ac is called the _______ of the quadratic equation. What does this value tell you about the real roots of the equation.
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
b%5E2-4ac is called the discriminant of the quadratic equation, x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29+. Note that this is the expression under the radical in the quadratic equation.

DELTA is the symbol for the discriminant, so DELTA=b%5E2-4ac

If DELTA=0 then there is a single root to the quadratic with multiplicity of 2 and that root is x=%28-b%29%2F2a. The term multiplicity of 2 arises from the fact that every quadratic can be represented as two factors: %28x-r%29%28x-s%29=0 where r and s can be either complex or real numbers. In the case of DELTA=0, r=s.

If DELTA%3E0 then there are two distinct real number roots.

If DELTA%3C0 then there is a conjugate pair of complex roots of the form alpha%2B-beta%2Ai where i is the imaginary number defined by i%5E2=-1