document.write( "Question 439286: Prove that the given statement is an identity.\r
\n" ); document.write( "\n" ); document.write( "1)(tan x - cot x)/ (tan x+cot x) = 2sin^2 x - 1
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Algebra.Com's Answer #303547 by MathLover1(20850)\"\" \"About 
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\"%28tan%28x%29+-cot%28+x%29%29%2F%28tan+x%2Bcot+x%29\"=2(sin^2)x\r
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\n" ); document.write( "\n" ); document.write( "use identities:\r
\n" ); document.write( "\n" ); document.write( "\"sin%28x%29+%2F+cos%28x%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"cot%28x%29+=+cos%28x%29%2F+sin%28x%29\"\r
\n" ); document.write( "\n" ); document.write( "prove that left side is equal to right side:\r
\n" ); document.write( "\n" ); document.write( "\"%28tanx+-cotx%29%2F%28tanx%2Bcot+x%29\" =2sin^2x -1\r
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\n" ); document.write( "\n" ); document.write( "\"%28sinx%2Fcosx+-cosx%2Fsinx%29%2F%28sinx%2Fcosx%2Bcosx%2Fsinx%29\" = 2sin^2 x - 1\r
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\n" ); document.write( "\n" ); document.write( "= 2sin^2 x - 1\r
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\n" ); document.write( "\n" ); document.write( "= 2sin^2 x - 1\r
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\n" ); document.write( "\n" ); document.write( "\"%28sin%5E2%28x%29-cos%5E2%28x%29%29%2F%28sin%5E2%28x%29%2Bcos%5E2%28x%29%29\"= 2sin^2 x - 1...notice that both nominator and denominator have sin and coc squared\r
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\n" ); document.write( "\n" ); document.write( "\"%28sin%5E2%28x%29-cos%5E2%28x%29%29%2F1\"= 2sin^2 x - 1\r
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\n" ); document.write( "\n" ); document.write( "replace cos^2x with \"1-sin%5E2%28x%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"sin%5E2%28x%29-%281-sin%5E2%28x%29%29\"= 2sin^2 x - 1\r
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\n" ); document.write( "\n" ); document.write( "\"sin%5E2%28x%29-1%2Bsin%5E2%28x%29\"= 2sin^2 x - 1\r
\n" ); document.write( "\n" ); document.write( "\"2sin%5E2%28x%29-1\"= 2sin^2 x - 1
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