maths problem ...

Discussion in 'General Discussions' started by ch1m0x, Oct 4, 2008.

  1. ch1m0x

    ch1m0x Newbie

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    i dunno how to solve this maths ... hiks .. im so desperate

    f(x) = ( 2x – 1 )² ( x + 2 ), f’(x) = ….
    f(x) = sin³ (3 – 2x). f’(x) = ….
    f(x) = sin² ( 2x + π/6 ), f′(0) = ….

    Plz help me .. deadline next week .. T____T
     
    #1 ch1m0x, Oct 4, 2008
  2. domini212

    domini212 Level III

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    What is the question? are you suppose to graph these? intersection pt?
     
    #2 domini212, Oct 4, 2008
  3. SoC

    SoC Moderator
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    Differentate

    F -> F'
    y -> dy/dx
     
    #3 SoC, Oct 4, 2008
  4. ch1m0x

    ch1m0x Newbie

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    thats the question ..

    f -> f'

    hmm ... i try figure out the answer ... hmm hmm
     
    #4 ch1m0x, Oct 4, 2008
  5. ch1m0x

    ch1m0x Newbie

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    this is the question for class XII student or high school in my country ...
     
    #5 ch1m0x, Oct 4, 2008
  6. Akoftl

    Akoftl Level I

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    #1 = 12x^2 + 8x - 7



    I'll edit this post with the rest of the answers when I'm done... It could be a few min its been a while since I've done differentiation

    EDIT: nvm SoC is going at it.. I need to do some reviewing >< I should be able to do this crap still ><
     
    #6 Akoftl, Oct 4, 2008
  7. SoC

    SoC Moderator
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    ( 2x – 1 )² = 4x^2-4x+1 = 8x - 4

    ( x + 2 ) = X+2 = 1

    1x(4x^2-4x+1) + (X+2)(8x-4)
    4x^2-4x+1 + 8x^2+12x-8

    12x^2+8x-7.

    Yeh #1 is right

    (Not done 2/3 yet)
     
    #7 SoC, Oct 4, 2008
  8. SoC

    SoC Moderator
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    Doulbe post to alert person above me

    I meant by not done 2/3 that i haven't studied that, so ive no idea :p

    sorry

    Good luck :)
     
    #8 SoC, Oct 4, 2008
  9. ch1m0x

    ch1m0x Newbie

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    is it difficult ?? SoC haven't studied that ?? hmm hmm ... really ??

    huhuhuhh ... its too difficult for me .. maths = 5*ck
     
    #9 ch1m0x, Oct 5, 2008
  10. Zer0

    Zer0 Level IV

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    Use chain rule ;)
    f'(g') = f'(g)g'
     
    #10 Zer0, Oct 5, 2008
  11. SoC

    SoC Moderator
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    Sin^3 and sin^2 isn't on our sylabus to learn.
    If i knew what sin^3 /Sin^2 differentated to, id be able to do it.
     
    #11 SoC, Oct 5, 2008
  12. ch1m0x

    ch1m0x Newbie

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    owh .. i see .. someone told me (whos living and school in NYC) .. the maths is more difficult in my country, Indonesia.
     
    #12 ch1m0x, Oct 5, 2008
  13. SoC

    SoC Moderator
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    It all depends on the sylabus and exam board and your countries education policies.

    The UK was heavily messed up by margaret thatcher and a load of corrupt politicians who have delayed it and made the education system RUBBISH!

    What age are you doing this at?
     
    #13 SoC, Oct 5, 2008
  14. ch1m0x

    ch1m0x Newbie

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    i'm 17 going 18 and prepare for final exam and ill go college.
     
    #14 ch1m0x, Oct 5, 2008
  15. SoC

    SoC Moderator
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    same age then
    So its probably just different topics covered

    Roughly the same difficulty :)
    so it's not too hard then tbh
     
    #15 SoC, Oct 5, 2008
  16. ch1m0x

    ch1m0x Newbie

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    btw, thx for helping me (the 1st) .. and ill find out the answer for 2/3

    someday, ill asking you for help ^^ ..

    but, how to translate it from my word to your word .. hehehehe ...

    thx SoC
     
    #16 ch1m0x, Oct 5, 2008
  17. SoC

    SoC Moderator
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    yw :)
    and ive just realised the question is f(x) = sin³ (3 – 2x)

    meaning you can rewrite it as f(X) = sin(3-2x)^3

    Which is then solveable, and you should be able to do via chain rule :)

    Hope that helps
     
    #17 SoC, Oct 5, 2008
  18. Akoftl

    Akoftl Level I

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    I used to have a formula that worked for solving trig chains simply... gotta go back in time to find it ><
     
    #18 Akoftl, Oct 5, 2008
  19. ch1m0x

    ch1m0x Newbie

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    ^

    heheheheh ... ganbatte ganbatte ...
     
    #19 ch1m0x, Oct 6, 2008