# Trigonometric function help please!

1. Mar 13, 2012

### newchie

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. Mar 13, 2012

### SammyS

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

$\displaystyle \frac{a+b+c}{e+f+g}\ne\frac{a}{e}+\frac{b}{f}+ \frac{c}{g}\ \ \$

3. Mar 13, 2012

### newchie

ah yes woops, i misread hehe, anyways do you have an aproach on this problem