GP general term (nth term) (nth term is first term times ratio raised to n−1)

jee-mainjee-advanced

nth term is first term times ratio raised to n−1

What each symbol means

SymbolWhat it stands for
aFirst term
nTerm index
rCommon ratio

When to use this

Geometric progression: each term is previous times r; r ≠ 0 for non-trivial use.