Geometric Sequence Calculator

Results:

Understanding Geometric Sequences

Basic Concepts

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

nth Term: aₙ = a₁rⁿ⁻¹

Sum of n Terms (r ≠ 1): Sₙ = a₁(1-rⁿ)/(1-r)

Sum of n Terms (r = 1): Sₙ = na₁

Sum of Infinite Terms (|r| < 1): S∞ = a₁/(1-r)

Common Ratio: r = aₙ₊₁/aₙ

Properties and Characteristics

Key Properties

  • Constant ratio between terms
  • Exponential growth/decay pattern
  • Geometric mean property
  • Terms form exponential function
  • Product of equidistant terms
  • Convergence conditions

Special Cases

  • Unit ratio (r = 1)
  • Negative ratio sequences
  • Alternating sequences
  • Convergent series (|r| < 1)
  • Divergent series (|r| > 1)
  • Oscillating sequences

Advanced Topics

Applications

  • Compound Interest
  • Population Growth
  • Radioactive Decay
  • Sound Wave Attenuation
  • Fractals and Self-Similarity
  • Musical Harmonics
  • Market Growth Models
  • Probability Distributions

Mathematical Analysis

Geometric Mean: GM = ⁿ√(a₁×a₂×...×aₙ)

Term Position: n = log_r(aₙ/a₁) + 1

Product Formula: aₖ×aₙ₋ₖ₊₁ = a₁×aₙ

Partial Products: Pₙ = a₁ⁿ×r^(n(n-1)/2)

Related Concepts

  • Power Series
  • Taylor Series
  • Complex Geometric Series
  • Infinite Products
  • Recursive Sequences
  • Continued Fractions

Convergence Theory

Ratio Test: lim|aₙ₊₁/aₙ| = |r| < 1

Root Test: lim|aₙ|^(1/n) = |r| < 1

Absolute Convergence: Σ|aₙ| < ∞