Find k (quadratic).

[alexs0uthern]

Find k if: The roots are real and different.
3x^2 + 2x + k = 0

 

[pka]

Find k if: The roots are real and different.
3x^2 + 2x + k = 0

The discriminant, \(\displaystyle b^2-4ac\), is named that because it discriminates between the kinds of roots.

If \(\displaystyle b^2-4ac>0\) there are two real roots.

 

[HallsofIvy]

Use the quadratic formula \(\displaystyle x= \frac{-b\pm\sqrt{b^2- 4ac}}{2a}\)

The roots will be "real and different" if and only if the "discriminant", \(\displaystyle b^2- 4ac\) is positive.