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Article #98

Re: Multiple angle help!!

#98
From: Jim Nastos
Date: Sun, 15 Sep 1996 00:00
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Al (joiced@omen.com.au) wrote:

: Would anyone please be able to shed some light on the above problem for me,
: as i have reached a mental block on finding a totally perfect pattern or
: rule to decide the expansion from simply sin nx or cos nx.

Hmmm... okay... but I just hope this isn't for homework, or something.

sin(nx) = n[cos(x)^(n-1)]*x*sin(x) - nC3(cos(x)^(n-3))*sin(x)^3 + 
nC5[cos(x)^(n-5)]*sin(x)^5 + ... 

for n = 2, 3, 4, ...
and nCr = n!/[(r!)(n-r)!]

cos(nx) = (cos(x))^n - nC2[cos(x)^(n-2)]*sin(x)^2 + 
nC4[cos(x)^(n-4)]*sin(x)^4 - ...

with n and nCr being the same as stated above.

-- 
Jim Nastos
Mathematics '00
University of Waterloo
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From: cd467@torfree.net (Jim Nastos)
Subject: Re: Multiple angle help!!
Date: 1996/09/15
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