document.write( "Question 39195: Still do not understand. Please help again.\r
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\n" ); document.write( "\n" ); document.write( "3) Use the geometric sequence of numbers 1, 1/3, 1/9 , 1/27… to find the following:
\n" ); document.write( "a) What is r, the ratio between 2 consecutive terms?
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\n" ); document.write( "\n" ); document.write( "b) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 10 terms? Carry all calculations to 7 significant figures.
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\n" ); document.write( "\n" ); document.write( "c) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 12 terms? Carry all calculations to 7 significant figures.
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\n" ); document.write( "\n" ); document.write( "d) What observation can make about these sums? In particular, what number does it appear that the sum will always be smaller than?
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Algebra.Com's Answer #24633 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
3) Use the geometric sequence of numbers 1, 1/3, 1/9 , 1/27… to find the following:
\n" ); document.write( "a) What is r, the ratio between 2 consecutive terms?
\n" ); document.write( "Answer:
\n" ); document.write( "Show work in this space.
\n" ); document.write( "r is the number which is used to multiply a term of the sequence to
\n" ); document.write( "get the following term of the sequence. So to determine \"r\" you need
\n" ); document.write( "to divide any term of the sequence by the term immediately preceding it.
\n" ); document.write( "For example, divide the 2nd term by the 1st term to get the following:
\n" ); document.write( "r = [1/3]/1= 1/3 \r
\n" ); document.write( "\n" ); document.write( "b) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 10 terms? Carry all calculations to 7 significant figures.
\n" ); document.write( "Answer:
\n" ); document.write( "Show work in this space.
\n" ); document.write( "The formula for the sum of \"n\" terms is as follows:
\n" ); document.write( "S(n)=a(1)[r^n-1]/[r-1]
\n" ); document.write( "a(1)=1 in your problem
\n" ); document.write( "So, the sum of the first 10 terms is as follows:
\n" ); document.write( "S(10)=1[r^10-1]/[r-1]= [(1/3)^10-1]/[1/3 - 1]
\n" ); document.write( "=-0.99998306.../(-2/3)1.49997460... \r
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\n" ); document.write( "\n" ); document.write( "c) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 12 terms? Carry all calculations to 7 significant figures.
\n" ); document.write( "Answer:
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\n" ); document.write( "Similarly the sum of the first 12 terms is as follows: \r
\n" ); document.write( "\n" ); document.write( "S(12)=1[(1/3)^12 - 1]/[(1/3)-1]= -0.99999812.../(-2/3)
\n" ); document.write( "=1.49999718... \r
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\n" ); document.write( "\n" ); document.write( "d) What observation can you make about these sums? In particular, what number does it appear that the sum will always be smaller than?
\n" ); document.write( "Answer:
\n" ); document.write( "As you take more and more terms the sum of the sequence of terms
\n" ); document.write( "gets closer and closer to 1.5\r
\n" ); document.write( "\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \r
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