Quadratic

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  1. zed963's Avatar
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    Quadratic
    What am I doing wrong on this question.

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  2. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by zed963)
    What am I doing wrong on this question.

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    just draw the line y=x^2-19 and find the solutions like you did with the other graph (first part of the question)

    hint - the easy way to draw y=x^2-19 is to draw y=x^2 and translate the graph "down" the y-axis by 19 units
    Last edited by Plato's Trousers; 22-07-2012 at 18:31.
  3. TenOfThem's Avatar
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    Re: Quadratic
    you needed the graph of y=5-2x
  4. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by Plato's Trousers)
    just draw the line y=x^2-19 and find the solutions like you did with the other graph

    hint - the easy way to draw y=x^2-19 is to draw y=x^2 and translate the graph "down" the y-axis by 19 units
    That is not the method required by the question
  5. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by TenOfThem)
    That is not the method required by the question
    tbh it's not that clear what method the question is asking for. And god knows what that stuff at the bottom is supposed to mean. y=-6 [2] x=-1 etc
  6. Plato's Trousers's Avatar
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    Re: Quadratic
    another way would be to draw y=-2x+5 and see where they intersect

    (work out what x^2-2x-14=-2x+5 gives you)
    Last edited by Plato's Trousers; 22-07-2012 at 19:00.
  7. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by Plato's Trousers)
    tbh it's not that clear what method the question is asking for
    It says --- by drawing a suitable line


    (Original post by Plato's Trousers)
    And god knows what that stuff at the bottom is supposed to mean. y=-6 [2] x=-1 etc
    They are zed's incorrect answers [and the marks available]
  8. steve2005's Avatar
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    Re: Quadratic
    (Original post by zed963)
    What am I doing wrong on this question.

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    The web site this question comes from is littered with errors.
  9. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by steve2005)
    The web site this question comes from is littered with errors.
    yeah. It's a pretty poor question, tbh. Rather ambiguous
  10. steve2005's Avatar
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    Re: Quadratic
    (Original post by Plato's Trousers)
    yeah. It's a pretty poor question, tbh. Rather ambiguous
    It's not ambiguous . The suggested solutions are simply rubbish.
  11. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by steve2005)
    It's not ambiguous . The suggested solutions are simply rubbish.
    and what is that random blue line doing on the graph?
  12. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by Plato's Trousers)
    and what is that random blue line doing on the graph?
    That will also be Zed's answer
  13. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by steve2005)
    The suggested solutions are simply rubbish.

    What suggested solutions?

    Where are you seeing errors from the site on the attachment given
  14. steve2005's Avatar
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    Re: Quadratic
    (Original post by TenOfThem)
    What suggested solutions?

    Where are you seeing errors from the site on the attachment given
    Sorry, I thought the 'answers' at the bottom were answers that the user had to select.
  15. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by steve2005)
    Sorry, I thought the 'answers' at the bottom were answers that the user had to select.
    this is what the page looks like

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    though i agree that the site is far from perfect
  16. TheGoat's Avatar
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    Re: Quadratic
    ..Just write the coordinates of the point where the line crosses the X and Y axis?
  17. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by TenOfThem)
    That will also be Zed's answer
    but he appears to have entered y= -6 as his answer. That blue line is not y= -6
  18. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by Plato's Trousers)
    but he appears to have entered y= -6 as his answer. That blue line is not y= -6
    No

    But we had already established that he did not know what he was doing

    Hence the thread
  19. TenOfThem's Avatar
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    Re: Quadratic
    (Original post by TheGoat)
    ..Just write the coordinates of the point where the line crosses the X and Y axis?
    This is not correct
  20. Plato's Trousers's Avatar
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    Re: Quadratic
    (Original post by TenOfThem)
    No

    But we had already established that he did not know what he was doing

    Hence the thread
    I thought you were saying he had to enter the line required in the y= box. Then the program would draw it on the graph? He hasn't entered the equation of that line so how did it appear on the graph?
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