Aplicație: Prisma optică

$$ \displaylines{ \delta = \text{deviația} \\ \begin{equation} \left. \begin{aligned} A = r + r' \ \\ \delta = i - r + (i' - r') \ \end{aligned} \right \vert \implies \begin{aligned} \delta = i + i' - A \\ \end{aligned} \end{equation} } $$ $$ \displaylines{ \delta_{min} \implies \begin{equation} \left. \begin{aligned} i = i' \ \\ r = r' \ \end{aligned} \right \vert \implies \begin{aligned} A = 2r \\ \delta = 2i - A \end{aligned} \end{equation} } $$