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#1 2008-11-23 21:23:49
- tony123
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cos(x - y)
Prove that if
and
,
then
Last edited by tony123 (2008-11-23 21:30:46)
#2 2008-11-24 10:23:59
#3 2008-11-24 10:27:04
- Daniel123
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Re: cos(x - y)
By inspection,
Last edited by Daniel123 (2008-11-24 10:27:22)
#4 2008-11-24 10:49:28
#6 2008-11-25 12:50:06
- JaneFairfax
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Re: cos(x - y)
By the way, you also need the condition
to ensure that and are not both .#7 2010-01-23 14:58:56
- jonecox
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Re: cos(x - y)
I know very well this expression.I am studying this function in school.I like your work.Thanks for share this information.
#8 2010-09-06 23:17:29
- sameer mishra
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Re: cos(x - y)
cosx +cosy=a
sinx-siny=b
squarring bot the equation then subtrac
cos2x+cos2y+2cox(x-y)=a2-b2
2cos(x-y)[1+cos(x+y)]=a^2-b^2 (o)
now squarring above equation then add
cos(x+y)
a^2+b^2)/2-1
now put the valu of cos(x+y) in (o)
cos(x-y)=a2 -b2/a2+b2
#9 2010-09-17 20:54:26
- sameer mishra
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Re: cos(x - y)
hello JaneFairfax i think that you are intresested in trigo.
but i challange you in trigo. calculus algebra. coordinate pleaseeeeeeeee
accept my challenge and ask question from me