document.write( "Question 897665: is the sequence 2, 6, 12, 20 arithmetic, geometric, or neither? \n" ); document.write( "

Algebra.Com's Answer #544218 by Edwin McCravy(20059) $\"\"$ $\"About$

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2, 6, 12, 20
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document.write( "Let's test it to see if it is arithmetic sequence:\r\n" );
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document.write( "(2nd term) - (1st term) = 6 - 2 = 4\r\n" );
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document.write( "(3rd term) - (2nd term) = 12 - 6 = 6  \r\n" );
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document.write( "The test fails.  4 and 6 aren't the same.  To be an arithmetic sequence,\r\n" );
document.write( "any term subtracted from the next term must always give the same number,\r\n" );
document.write( "called the common difference.  So it is not an arithmetic sequence, because\r\n" );
document.write( "4 and 6 are different.\r\n" );
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document.write( "Let's test it to see if it is geometric sequence:\r\n" );
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document.write( "The test fails also.  They aren't the same.  To be an geometric sequence,\r\n" );
document.write( "any term divided be the preceding term must always give the same number,\r\n" );
document.write( "called the common ratio.  So it is not a geometric sequence either.\r\n" );
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document.write( "It is neither an arithmetic nor a geometric sequence.\r\n" );
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document.write( "Edwin

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