Incercare

    \begin{displaymath} \mathbf{x}\left(k+1\right)=\mathbf{x}\left(k\right)+\left[\begin{array}{cccc} \delta_{d}\cdot{c\left(\alpha+\delta_{\alpha}\right)}\\ \delta_{d}\cdot{s\left(\alpha+\delta_{\alpha}\right)}\\ \delta_{\alpha} \end{array}\right] \end{displaymath}