Geometric Sequence

an=a1rn1a_n = a_1 \cdot r^{n-1}

Description

Finds the nth term of a geometric sequence.

Variables

Symbol Meaning
aₙ nth term
a₁ First term
n Term number
r Common ratio

Example

Problem

Find 5th term if a₁=2, r=3

Solution

a₅ = 2 × 3⁴ = 162

Real-World Applications

  • Compound interest
  • Population growth
  • Exponential decay