If $\overline{\mathrm{b}}, \overline{\mathrm{c}}$ are two unit vectors along the positive x, y axes, and $\overline{\mathrm{a}}$ is any vector, then $(\overline{\mathrm{a}}·\overline{\mathrm{b}})\overline{\mathrm{b}}+(\overline{\mathrm{a}}·\overline{\mathrm{c}})\overline{\mathrm{c}}+\frac{\overline{\mathrm{a}}·(\overline{\mathrm{b}}\times \overline{\mathrm{c}})}{{\left|\overline{\mathrm{b}}\times \overline{\mathrm{c}}\right|}^2}(\overline{\mathrm{b}}\times \overline{\mathrm{c}})=$