\[a_n = a_1 * r^(n-1)\]
Variables
annth term
a1first term
rcommon ratio
nterm index
Description
What is this formula?
This formula calculates the nth term of a geometric progression where each term is multiplied by a constant ratio.
When to use it
Use it when sequences grow or decay exponentially.
Example
a1=2, r=3, n=4 → a4=2*3^3=54
Applications
Finance, population growth, physics decay models.