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Homework Help: Trigonometric function help please!

  1. Mar 13, 2012 #1
    1. The problem statement, all variables and given/known data
    consider the function
    f(n,x) = (sinx+sin2x+sin3x +....+sin(n-1)x+sinnx)/)cosx+cos2x+cos3x+.....+cos(n-1)x+cosnx)
    Find the sum of all values for which f(23,x) = f(33,x)where x is measured in degrees from 100<x<200

    2. Relevant equations
    you get obviously tanx+tan2x....
    not sure where to go other than pluggin in values

    3. The attempt at a solution
    Plugging in values, testing cases trying different methods including demoivres, but doesent help. Help is appreciated!
  2. jcsd
  3. Mar 13, 2012 #2


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    You do not get tan(x)+tan(2x)+ ...

    [itex]\displaystyle \frac{a+b+c}{e+f+g}\ne\frac{a}{e}+\frac{b}{f}+ \frac{c}{g}\ \ \ [/itex]
  4. Mar 13, 2012 #3
    ah yes woops, i misread hehe, anyways do you have an aproach on this problem
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