document.write( "Question 730412: whats the exact value of cos 15
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Algebra.Com's Answer #446676 by Edwin McCravy(20055) $\"\"$ $\"About$

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document.write( "15° is the difference between the two special angles 45° and 30°\r\n" );
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document.write( "We use the formula\r\n" );
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document.write( "cos(A-B) = cos(A)cos(B) + sin(A)sin(B)\r\n" );
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document.write( "where A = 45° and B = 30°  \r\n" );
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document.write( "cos(15°) = \r\n" );
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document.write( "cos(45°-30°) = cos(45°)cos(30°) + sin(45°)sin(30°) = \r\n" );
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document.write( " +  = \r\n" );
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document.write( " +  = \r\n" );
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document.write( "Edwin

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