Math Is Fun Forum

123ronnie321

Member

Registered: 2010-09-28

Posts: 128

Trigonometry

sin(a) + sin(a+b) + sin(a+2b) +.....+ sin (a+nb) = ???

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Trigonometry

Hi 123ronnie321;

This is provided that n = 0,1,2,3,4,...

There is a formula for that particular sum. I used a computer instead.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

G_Einstein

Member

Registered: 2008-08-30

Posts: 124

Re: Trigonometry

sorry didn;t had time to write it correctly but I think that the result is correct  notice that cosa=cos(a)   ans sinna=sin(na)  but I had not time to wrote it .....

Last edited by G_Einstein (2010-10-17 03:58:24)

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