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Ch. 8 - Sequences, Induction, and Probability
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 9, Problema 19

Write a formula for the general term (the nth term) of each geometric sequence. Then use the formula for an to find a7, the seventh term of the sequence. 18, 6, 2, 2/3, ...

Guida verificata passo dopo passo
1
Identify the first term of the geometric sequence, which is \(a_1 = 18\).
Find the common ratio \(r\) by dividing the second term by the first term: \(r = \frac{6}{18}\).
Write the formula for the general term of a geometric sequence: \(a_n = a_1 \times r^{n-1}\).
Substitute the values of \(a_1\) and \(r\) into the formula to get the explicit formula for \(a_n\).
Use the formula to find the seventh term by substituting \(n = 7\) into \(a_n = a_1 \times r^{n-1}\).

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Geometric Sequence

A geometric sequence is a list of numbers where each term after the first is found by multiplying the previous term by a constant called the common ratio. For example, in the sequence 18, 6, 2, 2/3, ..., each term is obtained by multiplying the previous term by 1/3.
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Geometric Sequences - Recursive Formula

General Term Formula of a Geometric Sequence

The general term (nth term) of a geometric sequence is given by a_n = a_1 * r^(n-1), where a_1 is the first term, r is the common ratio, and n is the term number. This formula allows you to find any term in the sequence without listing all previous terms.
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Geometric Sequences - General Formula

Evaluating the nth Term

To find a specific term like the seventh term (a_7), substitute n = 7 into the general term formula. Calculate the power of the common ratio and multiply by the first term to get the value of the term directly.
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Nth Roots