Derivata di espressione radicalica
\(\displaystyle y = \sqrt { x^2 + 1 } \)
\(\displaystyle y' = { 1 \over 2 } \left( x^2 + 1 \right) ^{-1/2} \cdot 2 x = \)
\(\displaystyle = \left( x^2 + 1 \right) ^{-1/2} x = \)
\(\displaystyle = { x \over { \sqrt{ x^2 + 1 } } } \)