The match mini game

LESSON

SL 1.2 - Arithmetic Sequence and Series

What is an Arithmetic Sequence?

An arithmetic sequence is a sequence where the difference between consecutive terms is constant. This constant difference is called the common difference (usually denoted as d).

Key Formulas

For an arithmetic sequence with first term u1u_{1} common difference dd:

  1. The nth term formula: un=u1+(n1)du_{n} = u_{1} + (n-1)d

  2. The sum of n terms: Sn=n2[2u1+(n1)d]S_n = \frac{n}{2}[2u_{1} + (n-1)d]

Sigma Notation

The sum of a sequence can be written using sigma notation: k=1nuk\sum_{k=1}^{n} u_{k}

For arithmetic sequences, this equals SnS_n.