document.write( "Question 981304: Using techniques with sum and difference formulas, find any acceptable formula for cos 3(theta) You do not have to fully simplify your answer, but you must at least simplify identities.\r
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Algebra.Com's Answer #602359 by macston(5194)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "T=theta
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\n" ); document.write( "cos3T = cos(2T+T)...cos(a+b)=cos(a)cos(b)-sin(a)sin(b)
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\n" ); document.write( "cos3T = cos2TcosT-sin2TsinT...cos(2a)=cos^2(a)-sin^2(a) and sin(2a)=2sinTcosT
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\n" ); document.write( "cos3T = cosT(cos^2T-sin^2T)-sinT(2sinTcosT)
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\n" ); document.write( "cos3T = cos^3T-sin^2cosT-2sin^2TcosT
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\n" ); document.write( "cos3T = cos^3T-3sin^2TcosT...sin^2(a)=1-cos^2(a)
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\n" ); document.write( "cos3T = cos^3T-3(1-cos^2T)(cosT)
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\n" ); document.write( "cos3T = cos^3T-3(cosT-cos^3T)
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\n" ); document.write( "cos3T = cos^3T+3cos^3T-3cosT
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\n" ); document.write( "cos3T = 4cos^3T-3cosT\r
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