document.write( "Question 445211: if cos(x+y)=0.7547 and cos(x-y)=0.9703, then find the value of cos(x)cos(y). \n" ); document.write( "
Algebra.Com's Answer #306756 by AnlytcPhil(1806)\"\" \"About 
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document.write( " cos(x+y)=0.7547 and cos(x-y)=0.9703\r\n" );
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document.write( "find the value of cos(x)cos(y)\r\n" );
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document.write( "cos(x+y) = cos(x)cos(y) - sin(x)sin(y) = 0.7547\r\n" );
document.write( "cos(x-y) = cos(x)cos(y) + sin(x)sin(y) = 0.9703  Now add these eqs.:\r\n" );
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document.write( "          2cos(x)cos(y)                = 1.7250 \r\n" );
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document.write( "           \r\n" );
document.write( "          2cos(x)cos(y) = 1.7250\r\n" );
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document.write( "Divide both sides by 2:\r\n" );
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document.write( "           cos(x)cos(y) =  .8625\r\n" );
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document.write( "Edwin
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