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Trigonometric Proof

by likearollings
Tags: proof, trigonometric
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likearollings
#1
Mar15-11, 11:58 AM
P: 27
I am not quite sure how to prove this,

I can see it involves using a double angle formula (see http://mathworld.wolfram.com/Double-AngleFormulas.html).

I have tried working backwards but to no avail.

Any ideas?



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AlephZero
#2
Mar15-11, 01:07 PM
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Thanks
P: 6,953
Use
[tex]\sin a \cos b = (\sin (a+b) + \sin(a-b))/2[/itex]
likearollings
#3
Mar15-11, 01:12 PM
P: 27
Thanks! I will give that a go

likearollings
#4
Mar15-11, 01:29 PM
P: 27
Trigonometric Proof

Quote Quote by AlephZero View Post
Use
[tex]\sin a \cos b = (\sin (a+b) + \sin(a-b))/2[/itex]
Thanks, I managed to do it using

[tex]
\cos a \sin b = (\sin (a+b) - \sin(a-b))/2
[/tex]

PROBLEM SOLVED!


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