Math Problem Statement

Explicit: y=5(3 x )​

Recursive: n th value

previous value ⋅ 3 Recursive: n th value =previous value⋅3​

​The value of term number 6 6​ is 3645 3645​ and the sequence is being tripled​ at each step. ​Use one of the equations to find the value of term number 7 7​. Preview

Solution

We are given two forms of an equation for a sequence: explicit and recursive, and the sequence triples at each step.

Information Given:

  • The value of term n=6n = 6 is 3645.
  • The sequence triples at each step.

Recursive Formula:

The recursive formula can be used to find the next term: an=an1×3a_n = a_{n-1} \times 3 Where:

  • ana_n is the nn-th term.
  • an1a_{n-1} is the previous term.

We know a6=3645a_6 = 3645, so to find a7a_7 using the recursive formula: a7=a6×3=3645×3=10,935a_7 = a_6 \times 3 = 3645 \times 3 = 10,935

Thus, the value of the 7th term is 10,93510,935.

Explicit Formula:

The explicit formula for this geometric sequence is given by: y=5×3xy = 5 \times 3^x To find the 7th term, we substitute x=71=6x = 7 - 1 = 6 (since xx represents the position minus 1): y=5×36=5×729=3645y = 5 \times 3^6 = 5 \times 729 = 3645 Then for the 7th term: y=5×37=5×2187=10,935y = 5 \times 3^7 = 5 \times 2187 = 10,935

Both methods confirm the 7th term is 10,93510,935.

Would you like more details or have any further questions?


Here are 5 related questions for you to explore:

  1. What is the 8th term of this sequence using the recursive method?
  2. Can you derive the explicit formula for a different geometric sequence?
  3. How does the value of the common ratio affect the growth of the sequence?
  4. What is the sum of the first 7 terms in this sequence?
  5. How can you express this sequence in summation notation?

Tip: For geometric sequences, the ratio between consecutive terms stays constant.

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Math Problem Analysis

Mathematical Concepts

Sequences
Geometric Progression
Algebra

Formulas

Recursive formula: a_n = a_(n-1) ⋅ 3
Explicit formula: y = 5 ⋅ 3^x

Theorems

Geometric Sequence Formula

Suitable Grade Level

Grades 9-11