:'( help

Discussion in 'Off-Topic Chat' started by wewizrobbed, Mar 5, 2006.

  1. wewizrobbed

    wewizrobbed Member

    Anyone good at maths?! I'm stuck.

    evaluate in the form a + ib (with a and b real)

    e ^ (3-i[pi/3])

    :cry: :cry: :cry:

  2. bigmamabadger

    bigmamabadger Active Member

    If I take my socks off I can just about count up to 18. Sorry, no help at all. Sure somebody will though.:D
  3. Magic Flute

    Magic Flute Supporting Member

    All I know on that is that i = square root of -1 - but you probably already had that bit sorted!!
  4. wewizrobbed

    wewizrobbed Member

    :wink: yeah! thanks though....

    The assignment's due tomorrow and I've left it all too late again!!

    going to be a long night :(

    luce x
  5. DublinBass

    DublinBass Supporting Member

    What do you mean by evaluate?
  6. axio

    axio Member

    Okay it has been a while.. but here it goes...

    e ^ (3 - it) where t = pi / 3.
    can be expanded to
    (e^3) . (e^-it)

    as e ^ -it = cos(t) - i.sin(t)
    then the above can be written:
    (e^3) . (cos(t) - i.sin(t))

    expanding and grouping:
    real part (a) = (e^3) . cos(pi / 3)
    imag part (ib) = -i . (e^3) . sin(pi/3)

    Could be totally wrong of course.. like I say it has been a while.. but if it helps, it helps :)
  7. wewizrobbed

    wewizrobbed Member

    genious!! You're a star :D

  8. Lauradoll

    Lauradoll Active Member

    What??!!! Hope you got it done ok, brainy biiiiiiiach! Maybe see you on Saturday?
  9. TheMusicMan

    TheMusicMan tMP Founder Staff Member

    I see a new award category for the 48 months live awards this year, that of... "Most mind-boggling thread ':biggrin:
  10. Jan H

    Jan H Moderator Staff Member

    the "i" should not be included in the "imaginary part", I think.
    for a complaex number "a+ib", the imaginary part is "b"

    and of course sin(pi/3)=1/2 and cos(pi/3)=sqrt(3)/2

    so real part = (e^3).sqrt(3)/2
    and imag. part = -(e^3)/2


    (I hope I didn't make any stupid mistakes ;) )
  11. horn-girlie

    horn-girlie Member

    sounds about right (grr ... imaginary numbers:mad:)
  12. Craigsav83

    Craigsav83 Active Member

    Now I know why I ditched maths!
  13. wewizrobbed

    wewizrobbed Member

    haha my brain hurts now Laura!!

    Hopefully will make it along for a wee while on Saturday... will see if anyone else is going so I can scrounge a lift!

    Thanks to everyone for your help x x x
  14. axio

    axio Member

    Well of course.. but we had to leave something for her to do :D
  15. six pints

    six pints Active Member

    aww i remember the days when i didnt even know what imaginary numbers were... and now im preparing a presentation of the linear theory of waves. of course, i love maths, and i think laplace's equation is supercool!

  16. DaveR

    DaveR Active Member

    I still don't know, but I've survived this far without needing too so I won't worry too much. :(

    Mind you, looking at my bank statement I think imaginary numbers are probably those without a minus sign in front of them. :-?
  17. six pints

    six pints Active Member

    hmm i didnt think it was possible for bank accounts to go into plus numbers... im officially 62 quid past my overdraft limit. apparently thats bad (especially cos i need to pay that credit card bill... and i havent even bouhgt any new shoes for 5 months now)

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