KAtex problem - the style of equal sign alignment in CSDN editing

problem

Use CSDN Of "LaTeX" The grammar of I can't print the style of equal sign alignment （ The following figure shows the style you want ）：

Problem analysis

What's written here is LaTex The mathematical formula , But open the document link below , Open is KaTeX Its official website

KaTeX It's a Web Mathematical formula render , Part of the grammar may be related to LaTeX It's a little different , For example, the equal sign line feed I want here has a different effect on it

Problem solving

① CSDN First use $$ Enclose the mathematical formula you want to enter

$$   Content   $$

② After use \begin{aligned} And \end{aligned} Enclose the contents to be output in multiple lines

$$
\begin{
    aligned}
 The mathematical formula 
\end{
    aligned}
$$

③ Input mathematical formula , Use \\ Line break , Use & Control of equal sign position alignment .

$$
\begin{
    aligned}
d_{
    AB} 
&=\sqrt{
    (6-2)^2+(6-2)^2}\\
&=\sqrt{
    4^2+4^2}\\
&= 4\sqrt{
    2}
\end{
    aligned}
$$

• & = That is to say, let the equal sign be in the same position .

The effect is as follows ：

$$\begin{array}{rl}{d}_{AB}& =\sqrt{(6-2{)}^2+(6-2{)}^2}\\ & =\sqrt{4^2+4^2}\\ & =4\sqrt{2}\end{array}$$

For more information, please refer to the following links ：https://katex.org/docs/supported.html