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Geometric Sequence Recursive Rule Calculator

Geometric Sequence Recursive Formula:

\[ a_n = a_{n-1} \times r \]

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1. What is a Geometric Sequence?

A geometric sequence is a sequence of numbers where each term after the first is found by multiplying the previous term by a fixed, non-zero number called the common ratio.

2. Recursive vs Explicit Formulas

Recursive Formula: Defines each term based on the previous term

\[ a_n = a_{n-1} \times r \]

Explicit Formula: Defines any term directly using its position

\[ a_n = a_1 \times r^{n-1} \]

3. How the Calculator Works

The calculator takes the first term and common ratio, then generates both recursive and explicit formulas along with the first 5 terms of the sequence.

4. Using the Calculator

Tips: Enter the first term and common ratio. The common ratio cannot be zero. The calculator will display both recursive and explicit formulas along with the first 5 terms.

5. Frequently Asked Questions (FAQ)

Q1: What is the common ratio?
A: The common ratio (r) is the constant factor between consecutive terms in a geometric sequence.

Q2: Can the common ratio be negative?
A: Yes, a negative common ratio creates an alternating sequence where terms switch between positive and negative.

Q3: What if the common ratio is between 0 and 1?
A: The sequence will be decreasing (if first term is positive) and approach zero as n increases.

Q4: What if the common ratio is greater than 1?
A: The sequence will be increasing (if first term is positive) and grow without bound.

Q5: When would I use recursive vs explicit formulas?
A: Recursive formulas are useful for step-by-step calculations, while explicit formulas are better for finding specific terms directly.

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