## HighlyEducated87 Group Title Find the constant k so that the quadratic equation 2x^2 + 5x - k = 0 has two real solutions? one year ago one year ago

1. terenzreignz

2. aroub

First you find the delta: b^2-4ac 5^2-4(2)(-k) 25+8k because it has two real solutions..so, 25+8k>0 8k>-25 k>-25/8

3. HighlyEducated87

Good Job u got it 1st!!!!!

4. terenzreignz

$\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$ Yeah, as per @aroub delta (I thought it was discriminant) determines the number of roots you have, as well as their nature... Delta is that expression in the radical in the quadratic formula :D

5. HighlyEducated87

It is discriminant but i didn't need a quadratic formula.

6. aroub

When you want to find K, no need!

7. HighlyEducated87

i know!!! Thanks

8. aroub

No problem!!