PlayGround

<latex>

  \frac{3}{4 \pi}   \sqrt{4 \cdot x^2   12}\\
  \lim_{n \to \infty}
  \sum_{k=1}^n \frac{1}{k^2} = \frac{\pi^2}{6}\\
  \it{f}(x) = \frac{1}{\sqrt{x} x^2}\\

</latex>