Sigma Notation (Edexcel A-Level Mathematics): Flashcards

Sigma notation represents the sum of a series of terms.

$\sum_{k=m}^{n} a_k$ represents the sum of terms.

The index of summation is denoted by $k$.

It equals $15$, the sum of the first $5$ natural numbers.

It equals 30, which is $1^2 + 2^2 + 3^2 + 4^2$.

Linearity allows sums to be split or factored with constants.

Shift using $\sum_{j=m+c}^{n+c} a_{j-c}$ for constant $c$.

The sum is $36$: $1 + 3 + 5 + 7 + 9 + 11 = 36$.

The Greek letter Sigma ($\Sigma$) denotes summation.

Identify the general term $a_k$ before summation.