Damn - this is hard!

Discussion in 'General Chat' started by RadioBounce, Sep 20, 2010.

  1. #1
    OK, yet again I am in need of some assistance with my maths h/w.

    I've already attempted this but I can't seem to wrap my head around it.

    3x^2 + 12x + 5 = p(x + q)^2 + r.
    Code (markup):
    Help me PL0X.
     
    RadioBounce, Sep 20, 2010 IP
  2. RadioBounce

    RadioBounce Banned

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    #2
    Here's what I've got so far. I first have to find the value of p, q and r.

    (x+q) (x+q) + r/p
     
    RadioBounce, Sep 20, 2010 IP
  3. lifeplayer

    lifeplayer Notable Member

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    #3
    You cant get 4 unknown with 1 equation, you can only simplify the equation
     
    lifeplayer, Sep 20, 2010 IP
  4. lifeplayer

    lifeplayer Notable Member

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    #4
    Ops....now i understand the question, solution as below
    3x^2 + 12x + 5 = p(x + q)^2 + r
    3(x^2+4x+4)-7=p(x + q)^2 + r
    3(x+2)^2-7=p(x + q)^2 + r

    Therefore:
    p=3, q=2, r=-7
     
    lifeplayer, Sep 20, 2010 IP
  5. yogesh22

    yogesh22 Peon

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    #5
    Damn i have forgotten my maths. Iwould have defintely helped you if i remembered those formulae i need.
     
    yogesh22, Sep 20, 2010 IP
  6. RadioBounce

    RadioBounce Banned

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    #6
    Oh wow thanks.

    Guessing that most people on DP are a lot older than me, I'm surprised to see that they still remember this stuff. With me it seems to come in through one ear and go out the other ^^. LOL
     
    RadioBounce, Sep 20, 2010 IP
  7. lifeplayer

    lifeplayer Notable Member

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    #7
    Maths just a logic thinking, no need to remember


    By the way, teach you one very useful trick, use the replacement when you cant find the answer on this kind of question
    example:
    3x^2 + 12x + 5 = p(x + q)^2 + r

    Assume x=0
    5 = pq^2 + r
    assume x =1
    26 = p(1 + q)^2 + r
    assume x = -1
    2= p(q-1)^2 + r

    3 equation can get 3 unkown
     
    lifeplayer, Sep 20, 2010 IP
  8. RadioBounce

    RadioBounce Banned

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    #8
    I see... thanks =D
     
    RadioBounce, Sep 20, 2010 IP