2.3.26 Gradient and directional derivative

Condition: Find the derivative function \( \varphi=\frac{y^{2}}{x}+\frac{y^{2}}{z}+\frac{z^{2}}{x^{2}} \) at the point \( A(1,0,1) \) in the direction \( \overrightarrow{A B} \), where \( B(2,2,3) \).