Explore Westonci.ca, the top Q&A platform where your questions are answered by professionals and enthusiasts alike. Explore our Q&A platform to find reliable answers from a wide range of experts in different fields. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

Consider the sequences given in the table below. Find the least number, [tex]$n$[/tex], such that the [tex]$n$[/tex]th term of the geometric sequence is greater than the corresponding term in the arithmetic sequence.

\begin{tabular}{|l|c|c|c|c|c|c|c|c|}
\hline
Term Number & 1 & 2 & 3 & 4 & 5 & 6 & [tex]$\ldots$[/tex] & [tex]$n$[/tex] \\
\hline
Arithmetic & 200 & 700 & 1200 & 1700 & 2200 & 2700 & [tex]$\ldots$[/tex] & \\
\hline
Geometric & 2 & 4 & 8 & 16 & 32 & 64 & [tex]$\ldots$[/tex] & \\
\hline
\end{tabular}

The geometric sequence is larger than the arithmetic sequence at the [tex]$\square$[/tex]th term.


Sagot :

To solve the problem, we need to compare the [tex]$n$[/tex]th terms of the two given sequences and find the smallest [tex]$n$[/tex] such that the [tex]$n$[/tex]th term of the geometric sequence exceeds the [tex]$n$[/tex]th term of the arithmetic sequence.

1. Understand the sequences:
- The terms of the arithmetic sequence are given by:
[tex]\[ A_n = 200 + (n-1) \cdot 500 \][/tex]
- The terms of the geometric sequence are given by:
[tex]\[ G_n = 2 \cdot 2^{n-1} \][/tex]
Simplifying the geometric sequence formula:
[tex]\[ G_n = 2^n \][/tex]

2. Set the inequality:
We need to find the smallest [tex]$n$[/tex] such that:
[tex]\[ G_n > A_n \][/tex]
Substituting the expressions for [tex]$A_n$[/tex] and [tex]$G_n$[/tex], we get:
[tex]\[ 2^n > 200 + (n-1) \cdot 500 \][/tex]

3. Solve for [tex]\( n \)[/tex]:
Given in the solution, the sequences first satisfy the inequality when [tex]\( n = 13 \)[/tex]. At this stage:
- The [tex]$13$[/tex]th term of the arithmetic sequence (using the formula [tex]\( A_n = 200 + (n-1) \cdot 500 \)[/tex]):
[tex]\[ A_{13} = 200 + 12 \cdot 500 = 200 + 6000 = 6200 \][/tex]
- The [tex]$13$[/tex]th term of the geometric sequence (using the formula [tex]\( G_n = 2^n \)[/tex]):
[tex]\[ G_{13} = 2^{13} = 8192 \][/tex]

4. Comparison at the [tex]$13$[/tex]th term:
Clearly,
[tex]\[ 8192 > 6200 \][/tex]

This shows the geometric sequence is larger than the arithmetic sequence starting from the [tex]$13$[/tex]th term.

Thus, the geometric sequence becomes larger at the [tex]\(13\)[/tex]th term.
Thank you for your visit. We're committed to providing you with the best information available. Return anytime for more. Thanks for using our service. We're always here to provide accurate and up-to-date answers to all your queries. We're glad you visited Westonci.ca. Return anytime for updated answers from our knowledgeable team.