Sum of Arithmetic Series

S_n = \frac{n}{2}(a_1 + a_n)

Description

Calculates the sum of an arithmetic sequence.

Variables

Symbol	Meaning
`Sₙ`	Sum of n terms
`n`	Number of terms
`a₁`	First term
`aₙ`	Last term

Example

Problem

Sum of 1+2+3+...+100

Solution

S₁₀₀ = (100/2)(1+100) = 5050

Real-World Applications

Finance
Statistics
Problem solving