This is a test page
I'm going to write some math
E ( | A ∩ B | ) = n ∗ P ( i ∈ A ∩ B ) = n ∗ ( ( N − 1 n − 1 ) ( N n ) ) 2 = n 3 N 2 {\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>