# Problems of summation symbols and arrows in latex

Time：2021-9-3

### Summation symbol

Sum in latex (\ sum {}) For symbols\sum_{ Sum lower limit} ^ {sum upper limit}Write it out, as shown in the figure below:

\displaystyle
\sum_{i=1}^{N}

Note: don’t forget to write\displaystyleOtherwise, the following effect will appear:

\sum_{i=1}^{N}

### arrow

Arrow in latex \ rightarrow\rightarrowWrite it out, as shown in the figure below:

\rightarrow