# Math Help - index of summation

1. ## index of summation

How do you write the sum from i=1 to n with latex?

2. $$\sum_{i=1}^{n}$$

in this case the {n} is unnecessary, 'cause is just one element; if you want to type something like $\sum_{i=1}^{n-1},$ then you require to add the brackets {} for n-1.