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    Hi there. How would I go about doing this question below...?


    Would appreciate any help please!
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    Can anyone help please?
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    (Original post by Traceur)
    Can anyone help please?
    Is the answer x^3 - 5x^2 + 3x + 9 ? If so i can help you.
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    This is pretty straightforward

    Well you know that x =-1 and touches x at 3

    Which means you can compile the cubic via the inverse.

    (x+1) (x-3)(x-3)

    Muliply those out and you'll get: x^3- 5x^2 +3x+9=0

    As you can see clearly a=-5

    got it?
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    (Original post by marek35)
    This is pretty straightforward

    Well you know that x =-1 and touches x at 3

    Which means you can compile the cubic via the inverse.

    (x+1) (x-3)(x-3)

    Muliply those out and you'll get: x^3- 5x^2 +3x+9=0

    As you can see clearly a=-5

    got it?
    Ah of course! Thank you!
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    (Original post by Traceur)
    Ah of course! Thank you!
    no problem

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    I'm pretty sure you could also have done it with simultaneous equations as well, although it's slightly more strenuous and long winded! :P
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    Thanks for your answer but it surely seems to be much easier to use mareks solution...
    I did think to use simultaneous equations but its unnecessarily complicated (for me anyway).
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    (Original post by Traceur)
    Thanks for your answer but it surely seems to be much easier to use mareks solution...
    I did think to use simultaneous equations but its unnecessarily complicated (for me anyway).
    indeed solving it simultaneously would be pointless as you know where it crosses the x axis (or touches in this case too).
 
 
 
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