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    (Original post by lgs98jonee)
    wot does arg mean?
    Argument, the angle that the line to a point on an Argand diagram makes with the +ve real axis. I think the principal argument, Arg z is defined to be between -π and π.
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    (Original post by lgs98jonee)
    wot does arg mean?
    its the argument
    its angle from origin to the complex number in vector form. from pi to - pi
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    can someone gimme a hand with q8 on ex 3d in the p4 book? thanks.
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    (Original post by kikzen)
    can someone gimme a hand with q8 on ex 3d in the p4 book? thanks.
    Couldn't type it up could you? I don't have the text book
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    (Original post by Bezza)
    Couldn't type it up could you? I don't have the text book
    1/(x+iy) + 1/(1+2i) = 1

    x and y are real, find x and y.
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    (Original post by kikzen)
    1/(x+iy) + 1/(1+2i) = 1

    x and y are real, find x and y.
    [(1 + 2i) + (x + iy)]/(x + iy)(1 + 2i) = 1

    (1 + 2i) + (x + iy) = (x + iy)(1 + 2i)

    Multiply out the RHS and compare real and imaginary parts. I think.
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    (Original post by Nylex)
    [(1 + 2i) + (x + iy)]/(x + iy)(1 + 2i) = 1

    (1 + 2i) + (x + iy) = (x + iy)(1 + 2i)

    Multiply out the RHS and compare real and imaginary parts. I think.
    the bounds of my stupidity know no limits.

    danke.
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    (Original post by kikzen)
    1/(x+iy) + 1/(1+2i) = 1

    x and y are real, find x and y.
    Multiply by (x+yi)(1+2i):

    1 + 2i + x + yi = (x+yi)(1+2i)
    1 + 2i + x + yi = x + 2xi + yi - 2y
    1 + 2i = 2xi - 2y
    (xi - y) = ((1/2) + i)

    Compare real parts:

    -y = 1/2
    y = -1/2

    Im parts:

    x = 1

    I think...
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    (Original post by kikzen)
    the bounds of my stupidity know no limits.

    danke.
    Np. Does it work though?
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    (Original post by kikzen)
    1/(x+iy) + 1/(1+2i) = 1

    x and y are real, find x and y.
    1/(x+iy) = 1-1/(1+2i) = 2i/(1+2i)
    (x+iy) = (1+2i) /2i= 1/(2i)+1=1 - i/2
    so x=1 and y=-1/2
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    yes it works
 
 
 
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