Re: problemi di allineamento con amsmath e cases

`\begin{equation}
f_{Z}(z\vert B)=
\begin{cases}
\dfrac{2z}{\sqrt{3}\,l^{2}}\arccos\biggl(\dfrac{l}{2z}\biggr), & \dfrac{l}{2}\leq z\leq l, \\[2.5ex]
\dfrac{2z}{\sqrt{3}\,l^{2}}\arcsin\biggl(\dfrac{\sqrt{3}l}{2z}\biggr), & l