Math Problem Statement

The first three terms of a sequence are given: 14, 7, 7/2, and we need to find the 6th term.

Solution

The sequence provided is 14,7,72,14, 7, \frac{7}{2}, \dots. We need to find the 6th term.

This appears to be a geometric sequence where each term is obtained by multiplying the previous one by a constant ratio. Let's calculate the common ratio rr.

  1. The second term divided by the first term gives us: r=714=12r = \frac{7}{14} = \frac{1}{2}

  2. To confirm, divide the third term by the second term: r=727=12r = \frac{\frac{7}{2}}{7} = \frac{1}{2}

The common ratio is 12\frac{1}{2}. Now, we use the formula for the nn-th term of a geometric sequence: an=a1rn1a_n = a_1 \cdot r^{n-1} where:

  • a1=14a_1 = 14
  • r=12r = \frac{1}{2}
  • n=6n = 6

Substitute the values: a6=14(12)5=14132=1432=0.4375a_6 = 14 \cdot \left( \frac{1}{2} \right)^{5} = 14 \cdot \frac{1}{32} = \frac{14}{32} = 0.4375

Thus, the 6th term is 0.43750.4375.

Do you need more details or have any questions?

Here are 5 related questions to consider:

  1. What would be the 10th term in this sequence?
  2. How can you verify if a sequence is geometric?
  3. What is the sum of the first 6 terms of this sequence?
  4. How would the 6th term change if the ratio were 13\frac{1}{3} instead of 12\frac{1}{2}?
  5. How can we generalize the formula for an arithmetic sequence?

Tip: Always verify the common ratio by checking multiple terms, not just the first two.

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Math Problem Analysis

Mathematical Concepts

Sequences
Geometric Sequences
Common Ratio

Formulas

n-th term of a geometric sequence: a_n = a_1 * r^(n-1)

Theorems

Geometric Sequence Theorem

Suitable Grade Level

Grades 9-12