markdown大括号

$\{1,2,3,4,5\}$

{ 1 , 2 , 3 , 4 , 5 } {1,2,3,4,5} {1,2,3,4,5}

$f(i)=
\left\{\begin{matrix}
1,i\in Q \\
-1,i\notin Q
\end{matrix}\right.$

f ( i ) = { 1 , i ∈ Q − 1 , i ∉ Q f(i)=\left{\begin{matrix}1,i\in Q\-1,i\notin Q \end{matrix}\right. f(i)={1,i∈Q−1,i∈/​Q​

原文地址：https://blog.csdn.net/tanjunming2020/article/details/126877812?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522168905673016800227434001%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=168905673016800227434001&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~first_rank_ecpm_v1~rank_v31_ecpm-17-126877812-null-null.142^v88^control_2,239^v2^insert_chatgpt&utm_term=markdown