# Thread: Questions for exam tomorrow

1. ## Questions for exam tomorrow

C1 exam tormorrow, got some last minute questions.

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, has no real roots.

Find the set of possible values of k.

So I use $\displaystyle b2-4ac<0$?

If the question said:

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, has equal roots.

I would use: $\displaystyle \sqrt b2-4ac=0$?

And if the question said

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, 2 real roots.

I would use: $\displaystyle b2-4ac>0$?

2. Hi

Yes that's it
For the second example you made a typing error : $\displaystyle b^2 - 4ac = 0$

3. Originally Posted by Ifailatmaths
C1 exam tormorrow, got some last minute questions.

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, has no real roots.

Find the set of possible values of k.

So I use $\displaystyle b2-4ac<0$?

If the question said:

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, has equal roots.

I would use: $\displaystyle \sqrt b2-4ac=0$?

And if the question said

5.The equation $\displaystyle 2x^2 -3x - (k + 1) = 0$, where k is a constant, 2 real roots.

I would use: $\displaystyle b2-4ac>0$?
Precisely

4. Originally Posted by running-gag
Hi

Yes that's it
For the second example you made a typing error : $\displaystyle b^2 - 4ac = 0$
Typing error I thought I used a square root when its equal roots?

5. I only meant that you wrote $\displaystyle \sqrt b2-4ac=0$ instead of $\displaystyle b^2-4ac=0$

6. Originally Posted by running-gag
I only meant that you wrote $\displaystyle \sqrt b2-4ac=0$ instead of $\displaystyle b^2-4ac=0$

Ah gotcha, cheers.