Bayes' Theorem
$$ \Pr (A\vert B)=\frac{\Pr (A)\times \Pr (B \vert A)}{\Pr (B)} = \frac{\Pr (A)\times \Pr (B \vert A)}{\Pr (A)\times \Pr (B \vert A) + \Pr (\neg A)\times \Pr (B \vert \neg A)} $$
Array
$$ \left[ \begin{array}{ccc}
\lambda - a & -b & -c \
-d & \lambda - e & -f \
-g & -h & \lambda - i
\end{array}
\right] $$
Differential
$$ \iint xy^2,dx,dy =\frac{1}{6}x^2y^3, $$
Vector Problem
$$ u=\frac{-y}{x^2+y^2},,\quad v=\frac{x}{x^2+y^2},,\quad\text{and}\quad w=0,. $$