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Math Help - Trig

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    Trig

    If 2 sin(x-y)= sin(x+y), prove that tan x=3 tan y
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  2. #2
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    Quote Originally Posted by KingV15 View Post
    If 2 sin(x-y)= sin(x+y), prove that tan x=3 tan y
    2sin(x-y)-sin(x+y)=0

    [2sin(x)cos(y)-2cos(x)sin(y)]-[sin(x)cos(y)+cos(x)sin(y)] = 0

    3sin(x)cos(y) = cos(x)sin(y)

    You should be able to finish this off now, just remember that \frac{sin \theta}{cos \theta} = tan \theta
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