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    How do I go about finding the arguments of sin(4/7 pi) - icos(4/7 pi) and i + tan(2/7 pi)? I've only done in the form of cos(x) + isin(x) and I don't know how to change it to apply to these situations

    thanks
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    (Original post by bl64)
    How do I go about finding the arguments of sin(4/7 pi) - icos(4/7 pi) and i + tan(2/7 pi)? I've only done in the form of cos(x) + isin(x) and I don't know how to change it to apply to these situations

    thanks
    In general, one can write z=x+iy=re^{i \theta} with r=|z| and \theta =\arg(z) \in (-\pi,\pi].
    On the right hand half plane, one can write \arg(z)=\arctan \left(\dfrac{y}{x} \right).
    On the left hand half plane it may differ from \arctan\left(\dfrac{y}{x} \right) by the addition or subtraction of \pi depending on the sign of Im(z).

    Additional information:
    The above is known as the principal value of the argument, You could equally well define the argument on any other interval of width 2\pi.
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    (Original post by joostan)
    In general, one can write z=x+iy=re^{i \theta} with r=|z| and \theta =\arg(z) \in (-\pi,\pi].
    On the right hand half plane, one can write \arg(z)=\arctan \left(\dfrac{y}{x} \right).
    On the left hand half plane it may differ from \arctan\left(\dfrac{y}{x} \right) by the addition or subtraction of \pi depending on the sign of Im(z).

    Additional information:
    The above is known as the principal value of the argument, You could equally well define the argument on any other interval of width 2\pi.
    Btw you can use ["tex"] (sans the quotes) instead of ["latex"] and \Im for the imaginary part function, though many people might not recognize it because it looks like this: \Im .
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    (Original post by gagafacea1)
    Btw you can use ["tex"] (sans the quotes) instead of ["latex"] and \Im for the imaginary part function, though many people might not recognize it because it looks like this: \Im .
    Yeah, I know, but there are some options that \tex doesn't cover, so I use \latex for all the difference it makes
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    (Original post by gagafacea1)
    Btw you can use ["tex"] (sans the quotes) instead of ["latex"] and \Im for the imaginary part function, though many people might not recognize it because it looks like this: \Im .
    And you can write [tex]some command[/tex] using "[noparse][tex]some command[/tex][/noparse]".
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    (Original post by joostan)
    Yeah, I know, but there are some options that \tex doesn't cover, so I use \latex for all the difference it makes

    (Original post by Kvothe the arcane)
    And you can write [tex]some command[/tex] using "[noparse][tex]some command[/tex][/noparse]".
    Oh thanks!! The more you know.
 
 
 
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