SOLUTION: Can you prove this identity: {{{sin(3x)/sin(x)}}} - {{{cos(3x)/cos(x)}}} = 2

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Question 608410: Can you prove this identity:
sin%283x%29%2Fsin%28x%29 - cos%283x%29%2Fcos%28x%29 = 2
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Can you prove this identity:
sin%283x%29%2Fsin%28x%29 - cos%283x%29%2Fcos%28x%29 = 2
Get an LCD on the left side of sin(x)·cos(x) 

%28sin%283x%29cos%28x%29-cos%283x%29sin%28x%29%29%2F%28sin%28x%29cos%28x%29%29

Use the identity sin(A)cos(B)-cos(A)sin(B) = sin(A-B) 

sin%283x-x%29%2F%28sin%28x%29cos%28x%29%29

sin%282x%29%2F%28sin%28x%29cos%28x%29%29

Use the identity sin(2θ) = 2sin(θ)·cos(θ)

%282sin%28x%29cos%28x%29%29%2F%28sin%28x%29cos%28x%29%29



2

Edwin