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December 20, 2014

December 20, 2014

Posted by **xX_Supaman_Xx** on Sunday, December 2, 2007 at 6:12pm.

sin(c+h)=sin(c)xcos(h)+cos(c)xsin(h)

but how?

please explain

- Reposted: Maths - Trig -
**drwls**, Sunday, December 2, 2007 at 6:31pmHere you will find a proof of that trigonometric identity:

http://library.thinkquest.org/C0110248/trigonometry/formsine.htm

- Reposted: Maths - Trig -
**Reiny**, Sunday, December 2, 2007 at 6:56pmHere is another approach to the proof

http://www.themathpage.com/aTrig/sum-proof.htm

(there seems to be a 'spacing' problem in the html code in the first few lines, but I am sure you know what the equation should read )

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