先放一个LateX查询文档在这以便查询

试用：

121x+1y+1x+y3\frac 1 2 \\ \frac{\dfrac 1 x+1}{y+1}\\ \sqrt[3]{x+y}

lim⁡x→0xsin⁡x\lim_{x \to 0} \frac{ x}{\sin x}\\

∣A⃗∣=Ax2+Ay2+Az2. |\vec{A}|=\sqrt{A_x^2 + A_y^2 + A_z^2}.

P(Ai∣B)=P(B∣A)P(Ai)∑j=1nP(Aj)P(B∣Aj)P(A_i \mid B) = \frac{P(B\mid A)P(A_i)}{\sum_{j=1}^{n}P(A_j)P(B \mid A_j)}

∂E∂xl=∂E∂xL∂xL∂xl=∂E∂xL(1+∂∂xl∑i=lL−1F(xi,Wi))\begin{split} \frac{\partial{\mathcal{E}}}{\partial{x_l}} & = \frac{\partial{\mathcal{E}}}{\partial{x_L}}\frac{\partial{x_L}}{\partial{x_l}}\\\\ & = \frac{\partial{\mathcal{E}}}{\partial{x_L}}\Big(1+\frac{\partial{}}{\partial{x_l}}\sum_{i=l}^{L-1} \mathcal{F}(x_i,\mathcal{W}_i)\Big) \end{split}

A=[a11a12...a1na21a22...a2na31a22...a3n⋮⋮⋱⋮an1an2...ann],b=[b1b2b3⋮bn]A = \begin{bmatrix} a_{11} & a_{12} & ... & a_{1n}\\ a_{21} & a_{22} & ... & a_{2n}\\ a_{31} & a_{22} & ... & a_{3n}\\ \vdots & \vdots & \ddots & \vdots\\ a_{n1} & a_{n2} & ... & a_{nn}\\ \end{bmatrix} , b = \begin{bmatrix} b_{1} \\ b_{2} \\ b_{3} \\ \vdots \\ b_{n} \\ \end{bmatrix}