equation systems: \begin{equation} 1 + 2 = 3 \ 1 = 3 - 2 \end{equation} align text \begin{align} 1+2 &= 3\newline f(x) &= x^2\ g(x) &= \frac{1}{x}\ F(x) &= \int^a_b \frac{1}{3}x^3\ \nabla b& = \int x^2dx \end{align} center a formula :…

1.向量 $\vec a$\qquad $\overleftarrow{AB}$\qquad $\overleftrightarrow{AB}$\qquad $\overrightarrow{AB}$ 2.插入图片 \section{测试插入图片1} \includegraphics[scale=0.4]{noise.jpg} \section{测试插入图片2} \begin{figure}[ht] \includegraphics[scale=0.4]{noise.jpg} \caption{…