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# AQA C1 Discriminant question help watch

1. I'm stuck on the following question 7a(ii) attached:

From the June 2010 AQA C1 paper, heres my working for the question:

In the mark scheme it said something completely different to what I did, it says this:

I do not understand how it has come up with that working and in equalities to work out the answer, I understand b^2 - 4ac > 0 for real roots however I don't know why it does it for the 3 seperately, then the (x-5)^2 seperately as well as having a > with a line underneath?

Can someone explain to me how I can answer this question simply please?
2. once you have completed the square you can read off the vertex coordinates. if the vertex is above the x axis and the graph is a U shape it will have no real roots
3. (Original post by the bear)
once you have completed the square you can read off the vertex coordinates. if the vertex is above the x axis and the graph is a U shape it will have no real roots
ah I understand now, so the 3 > 0 in the mark scheme basically means the y value of the vertex is greater than 0 therefore there is no real roots possible as it is a 2x^2 graph
4. (Original post by Sayless)
ah I understand now, so the 3 > 0 in the mark scheme basically means the y value of the vertex is greater than 0 therefore there is no real roots possible as it is a 2x^2 graph

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