document.write( "Question 1198622: Is the following series, 5 -10/3 +20/9 -40/27.
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document.write( "Convergent, or divergent?One of the following is the correct answer. Which one?\r
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document.write( "A) divergent
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document.write( "B) convergent \n" );
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Algebra.Com's Answer #832240 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Answer: Convergent\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Reason:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The jump from 5 to -10/3 is \"times -2/3\" \n" ); document.write( "The jump from -10/3 to 20/9 is \"times -2/3\" \n" ); document.write( "The jump from 20/9 to -40/27 is \"times -2/3\"\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We see that this sequence is geometric with common ratio r = -2/3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Because -1 < r < 1, this particular infinite geometric series is convergent.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Extra info: \n" ); document.write( "To compute the value of 5 - 10/3 + 20/9 - 40/27 + ... \n" ); document.write( "we'll use this formula \n" ); document.write( "S = a/(1-r) \n" ); document.write( "where in this case, a = 5 is the first term. \n" ); document.write( "So, \n" ); document.write( "S = a/(1-r) \n" ); document.write( "S = 5/(1-(-2/3)) \n" ); document.write( "S = 3 \n" ); document.write( "The infinitely many terms add up to 3. \n" ); document.write( "Realistically we can only add up finitely many terms, which means the sum will steadily approach 3 but never actually arrive at this exact value. \n" ); document.write( " \n" ); document.write( " |