note：math block for markdown

Code:[Inline Math Formula]

This formula $$f(x)=x_{1}^{2}+x_{2}^{2}$$ is an inline formula

preview:

This formula $f(x)=x_{1}^{2}+x_{2}^{2}$ is an inline formula

Code:[Fraction]

$$
f(x) = x^2+dfrac{1}{x}
$$

preview:

$$f(x) = x^2+dfrac{1}{x}$$

Code:[Set]

$$
D = {(x_1,y_1),(x_2,y_2),…,(x_n,y_n)}
$$

preview:

$D = {(x_1,y_1),(x_2,y_2),…,(x_n,y_n)}$
—-

Code:[Sum]

$$
　(w^{*},b^{*})= arg   min_{left( w,bright)} sum^{n}_{i=1}left(y_{i}-wx_{i} - bright)^{2}
$$

preview:

$$(w^{*},b^{*})= arg min_{left( w,bright)} sum^{n}_{i=1}left(y_{i}-wx_{i} - bright)^{2}$$

Code:[Matrix]

$$
X = begin{bmatrix}
x_{11}&x_{12}&cdots&x_{1d}&1\
x_{21}&x_{22}&cdots&x_{2d}&1\
vdots&vdots&ddots&vdots&vdots\
x_{n1}&x_{n2}&cdots&x_{nd}&1\
end{bmatrix}
$$

preview:

$$% <![CDATA[ X = begin{bmatrix} x_{11}&x_{12}&cdots&x_{1d}&1 \ x_{21}&x_{22}&cdots&x_{2d}&1\ vdots&vdots&ddots&vdots&vdots\ x_{n1}&x_{n2}&cdots&x_{nd}&1\ end{bmatrix} %]]>$$

Code:[Piecewise functions]

$$
y = 
begin{cases}
0, &z<0cr
0.5, &z=0cr
1, &z>0cr
end{cases}
$$

preview:

$$% <![CDATA[ y= begin{cases} 0, &z<0cr 0.5, &z=0cr 1, &z>0cr end{cases} %]]>$$

Code:[Hat]

$$
Var[hat{f}(x)] = E[hat{f}(x)-E[hat{f}(x)]^2]
$$

preview:

$$Var[hat{f}(x)] = E[hat{f}(x)-E[hat{f}(x)]^2]$$

Code:[Set Belong]

$$
rho = dfrac{sum_{x in hat{D}}w_x}{sum_{x in D}w_x}
$$

preview:

$$rho = dfrac{sum_{x in hat{D}}w_x}{sum_{x in D}w_x}$$

Code:[Arrow]

$$
lim _{mrightarrow infty }left( 1-dfrac {1}{m}right) ^{m}rightarrow dfrac{1}{e}
$$

preview:
$lim _{mrightarrow infty }left( 1-dfrac {1}{m}right) ^{m}rightarrow dfrac{1}{e}$

Code:[Integrate]

$$
int_{0}^{1}x^{2}dx
$$

preview:
$int_{0}^{1}x^{2}dx$

Code:[Space]

$$
f(x_i) = wx_i+b       s.t.    f(x_i) approx y_i
$$

preview:
$f(x_i) = wx_i+b s.t. f(x_i) approx y_i$