ABCHLMaths - Arithmetic Series

Arithmetic Series

Formula for Arithmetic Series

$S_n=frac{n}{2}( a_1 + a_n)=frac{n}{2}[ 2a_1 + (n-1)d].$

S_n=frac{n}{2}( a_1 + a_n)=frac{n}{2}[ 2a_1 + (n-1)d].

These are the two formulas

"S" is the sum of the arithmetic series
"n" is the number of terms
"a" is the arithmetic term
"d" is the difference