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    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?
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    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
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    (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
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    (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
    :borat:
 
 
 
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