If sinx/siny=1/2 and cos x/cosy=3 provethat
sin(x+y)=7/3 sin x cosx
Last edited by Tiger; Dec 5th 2009 at 09:45 PM.
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Originally Posted by Tiger If sinx/siny=1/5 and cos x/cosy=3 provethat
sin(x+y)=7/3 sin x cosx I don't think what you wrote is correct
sin(x + y) = sin(x)cos(y) + sin(y)cos(x)
replacing cos(y) and sin(y) with their equivalent expressions from the given equations, we can write sin(x + y) in terms of sin(x)cos(x). But the answer you gave won't be the right one.
Yeah made a mistake.
Originally Posted by Tiger Yeah made a mistake. ok, well, do as i said and you will get the answer.
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