Method of differences (polynomial-type general term) (Successive differences of terms reduce degree; constant kth difference ⇒)

jee-mainjee-advanced

Successive differences of terms reduce degree; constant kth difference ⇒ tₙ is degree k polynomial

What each symbol means

SymbolWhat it stands for
ΔForward difference operator
t_nnth term of sequence

When to use this

Applies when tₙ is polynomial in n; use to find explicit tₙ or sum via Σ.