Template:Big Sigma/doc

From Summation.

Without
Mathematical notation uses a symbol that compactly represents summation of many similar terms: the summation symbol,, an enlarged form of the upright capital Greek letter sigma. This is defined as ai = am + am + 1 + am + 2 + ... + an - 1 + an

where i is the index of summation; ai is an indexed variable representing each term of the sum; m is the lower bound of summation, and n is the upper bound of summation.

With
Mathematical notation uses a symbol that compactly represents summation of many similar terms: the summation symbol, $$, an enlarged form of the upright capital Greek letter sigma. This is defined as $a_{i} = a_{m} + a_{m + 1} + a_{m + 2} + ... + a_{n - 1} + a_{n}$

where $i$ is the index of summation; $a_{i}$ is an indexed variable representing each term of the sum; $m$ is the lower bound of summation, and $n$ is the upper bound of summation.