Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Power of complex number

  1. Nov 16, 2009 #1
    how to find number [tex](3-i)^{12}[/tex] ?

    i know theorem for powers of complex numbers, but i have to know argument of trygonometrical form.

    and its [tex] cos x = 3/4[/tex] and [tex]sin x = -1/4[/tex]

    and i dont know what to do with that.
  2. jcsd
  3. Nov 16, 2009 #2
    First write [itex]3 - i [/itex] in the form [itex]r (\cos\theta + i \sin \theta)[/itex] . Then [itex](3 - i)^{12} [/itex] will be [itex]r^{12} (\cos(12 \theta) + i \sin (12 \theta))[/itex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook