What's sin2A in the terms of A?
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- Thread Starter
- 29-01-2010 19:29
- 29-01-2010 19:34
If you have come across the formula for expanding
sin(A+B), you will remember that you get
This is the case where A = B
so you get 2sinAcosA
- 29-01-2010 19:35
_ravi_ is wrong about the first bit.
sin(A+B) = sinAcosB + cosAsinB
so yeah, sin2A = sin(A+A) = sinAcosA + cosAsinA = 2sinAcosA
- 29-01-2010 19:38
Wikipedias's Trigonometric Identities is your friend.