0

sinx+sin(x+a)+sin(x+2a)+.....sin(x+(n-1)a)

If we try to approach by basics then it would take a long time.Instead I tried solving it using complex numbers and De Moivre's Theorem and I was able to get the answer in terms of product of exponential and trig functions.But I am unable to bring out the answer in purely trigonometric form.Can you help me out with that?

Answer in terms of former is sinx*(e^(a*n)-1)/(e^(a)-1)

Ronak Nahata
  • 23
  • Do you know the result when angles are in AP – Archis Welankar Nov 07 '16 at 16:53
  • I don't get your point – Ronak Nahata Nov 07 '16 at 16:57
  • I think you should check your work, or even better edit the question to show how you got the result you got. It's hard to tell for sure because of the lack of formatting, but I think you may already have misapplied one of the rules for converting exponentials to trig functions. Compare http://math.stackexchange.com/questions/17966. To make your formulas more readable (and reduce misunderstanding), follow the advice in http://meta.math.stackexchange.com/questions/5020. – David K Nov 07 '16 at 18:33

0 Answers0