Vectorizing a function, apply the function on each element in the numpy array.
$$x = \begin{bmatrix} 0 & 3 & 4 \ 2 & 6 & 4 \ \end{bmatrix}\tag{3}$$ then $$| x| = np.linalg.norm(x, axis = 1, keepdims = True) = \begin{bmatrix} 5 \ \sqrt{56} \ \end{bmatrix}\tag{4} $$and $$ x_normalized = \frac{x}{| x|} = \begin{bmatrix} 0 & \frac{3}{5} & \frac{4}{5} \ \frac{2}{\sqrt{56}} & \frac{6}{\sqrt{56}} & \frac{4}{\sqrt{56}} \ \end{bmatrix}\tag{5}$$