document.write( "Question 1134076: cos(x+y)cos(x-y)=
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Algebra.Com's Answer #751391 by Edwin McCravy(20060) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "Use the two identities:\r\n" );
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document.write( "Multiply left sides and right sides:\r\n" );
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document.write( "Multiply out the right side \r\n" );
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document.write( " <-- possible final answer\r\n" );
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document.write( "That may be far enough for your teacher, but you can keep \r\n" );
document.write( "going if you desire.  Use these two identities:\r\n" );
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document.write( " and \r\n" );
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document.write( "Solve them for the squared terms.\r\n" );
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document.write( " and \r\n" );
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document.write( " and \r\n" );
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document.write( "Substitute in\r\n" );
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document.write( "Edwin

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