SOLUTION: For the quadratic equation 2x^2 + bx + 3 = 0, explain how to find a value of b where the discriminant yields a quadratic equation with the following types of solutions. A. two im

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: For the quadratic equation 2x^2 + bx + 3 = 0, explain how to find a value of b where the discriminant yields a quadratic equation with the following types of solutions. A. two im      Log On


   



Question 1094145: For the quadratic equation 2x^2 + bx + 3 = 0, explain how to find a value of b where the discriminant yields a quadratic equation with the following types of solutions.
A. two imaginary solutions
B. one real solution
C. two rational solutions
D. two irrational solutions

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!

With the standard form of a quadratic equation
y+=+ax%5E2%2Bbx%2Bc
the discriminant
b%5E2-4ac
in the quadratic formula determines which of these different cases you have.

(1) If the discriminant is negative, there are no real solutions -- i.e., case A: two imaginary solutions.
(2) If the discriminant is zero, there is a single real solution: case B.
(3) If the discriminant is positive, then there are two real solutions. Furthermore, the solutions are rational if the discriminant is a perfect square (case C), or they are irrational if the discriminant is not a perfect square (case D).

With your quadratic, the discriminant is
b%5E2-4%282%29%283%29+=+b%5E2-24

So you have...
Case A, if b^2 is less than 24;
Case B, if b^2 is equal to 24;
Case C, if b^2-24 is a positive perfect square; and
Case D, if b^2-24 is positive but not a perfect square.