Maths help.

Discussion in 'General' started by Stickeh, 17 Apr 2004.

  1. Stickeh

    Stickeh Help me , Help you.

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    eek i forgot to type anything in the thread - lol
    here goes.
    1. Simplify - (3xy³)²

    2. Solve equation - 2x²-5x-4=0

    3. P is inversely proportional to the square root of Q
    If P=12 when Q=49 find an expression for P in the terms of Q.

    if you can help please do!
     
  2. ajack

    ajack rox

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    1 + 1 = 2
     
  3. kenshin

    kenshin Banned

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    2 / 2 = 1
     
  4. Stickeh

    Stickeh Help me , Help you.

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    lol i know i forgot to to type anything auto hit ENTER instead of TAB lol.
     
  5. Ubermich

    Ubermich He did it!

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    5 / 2 = 2
    5 % 2 = 1

    5 / 2 * 2 = 4
    5 % 2 = 1
    ((5 / 2) * 2) + (5 % 2) = 5

    correct me if I missed something.
     
  6. Stickeh

    Stickeh Help me , Help you.

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    ok not funny any more... please i need the help.
     
  7. ajack

    ajack rox

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    [EDIT] nah that was wrong...
     
  8. kenshin

    kenshin Banned

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    1) 9x² * y^6

    3) P= A
    Q^0.5​

    12 = A
    7​

    P= 84Q


    Can you check question two as i get roots which arent at gcse level.
     
    Last edited: 17 Apr 2004
  9. BjD

    BjD What's a Dremel?

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    2) dotn think it factorises cleanly at first glance, use the quadratic equation (x=-b+- squareroot(b^2-4ac) /2a) think thats how it goes :D

    3) P=-k * squareroot(Q)

    sub P&Q to find k :thumb:
     
  10. kenshin

    kenshin Banned

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    -b ± squareroot (b²-4ac)
    2a
     
  11. Stickeh

    Stickeh Help me , Help you.

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    i dont know that equation :waah:
    im in year 11, prolly have learnt it just forgot
     
  12. kenshin

    kenshin Banned

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    you defo do the quadratic equation at gcse.
     
  13. cpu121

    cpu121 What's a Dremel?

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    1) 9 * x^2 * y^6 (y^n)^a = y^n*a

    2) -(-5) ± √ 5^2 - 4x2x-4
    ................2 x 2

    5 ± √25 -(-32)
    ..........4

    5 + √57 5 - √57
    .......4....................................4

    5 + 7.549834435 5 - 7.549834435
    ,,...........4...................................4

    12.7549834435 -2.7.549834435
    ..........4..................................4

    x = -0.6374586088 or 3.137458609 Round as required.

    3) P = 84 * (1 / √q)

    Hope that helps
     
    Last edited: 17 Apr 2004
  14. BjD

    BjD What's a Dremel?

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    ahh ah, i see i made a small error in my other post :D it should be...
    P=k * (1/root(Q))

    so sub for P&Q to find k :thumb:
     
  15. Der Me!$ter

    Der Me!$ter What's a Dremel?

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    2) Don't know if you mean -2x²-5x-4=0 or 2x²-5x-4=0

    anyway using the quadradic equation (-b ± sqrt(b²-4ac))/2a:

    a = (-)2
    b = -5
    c = -4

    plug'em in et voila (-2x²-5x-4=0):

    x1 = 11/2
    x2 = 8

    or if it should be 2x²-5x-4=0

    x1 = 21/2
    x2 = 8

    I learnt that formula in 10th grade igcse as well...
     
  16. Sanchos

    Sanchos What's a Dremel?

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    -b ± squareroot (b²-4ac)
    2a

    The method is actually given to you in the gcse paper, with how to find the area of sphere ect, therefore u dont need to memorise that method, just how to use it to solve quadratics.
     
  17. kenshin

    kenshin Banned

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    there is also completing the square but i wont get into that :baby:
     

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