TestPage

This is a test page

I'm going to write some math

Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle E(|A\cap B|)=n*P(i\in A\cap B)=n*\left({\frac {\binom {N-1}{n-1}}{\binom {N}{n}}}\right)^{2}={\frac {n^{3}}{N^{2}}}}

I hope that works

<HTML5video width="640" height="360" autoplay="false">Polar2</HTML5video>

Final Answer:
The final solution is the portion of the graph that below $y=\vert x\vert +1$ and inside Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x^2 + y^2 = 9}