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1. When I'm asked let's say find k from a quadratic equation .
I have to find the set of possible value of knursing discriminats, my question is when you find the discfimant of the quadratic equation with the k the constant I'm left with a quadratic what does it represent ? Is it y value or x?

I.e. k^2-4k-12 -----> (k-6)(k+2) so k is either -2 or 6 what does this show?
2. Oopsie
3. (Original post by FrostedStarzzz)
When I'm asked let's say find k from a quadratic equation .
I have to find the set of possible value of knursing discriminats, my question is when you find the discfimant of the quadratic equation with the k the constant I'm left with a quadratic what does it represent ? Is it y value or x?

I.e. k^2-4k-12 -----> (k-6)(k+2) so k is either -2 or 6 what does this show?
Er... I THINK I know what you're asking...

The typical question would be "Find the values of for which the equation has no real roots"

Then you know that for no real roots you need to have so . This equation represents a condition on , with which the above quadratic has no real roots. You want to simplify this condition down into something like or something. So we have and now you can draw this separate parabola in on a different axis, say the ky axis, and observe for what values of this equation is below the y-axis. The roots of this quadratic in are important because that's where the quadratic goes from being +ve to -ve.

So sketching this you'd find that the graph dips below y=0 in the region and this is the simplified condition the question wants to see.

In your example, I dunno what quadratic you started off with, but I assume the question was to find the values of for which it has equal roots. So you found your to be so or and these represent conditions again on for which the discriminant of the quadratic =0 which implies that the quadratic has equal roots.

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