$-2\sqrt{2}$-2\sqrt{2}

$\displaystyle \frac{\sqrt{2}}{2}$\displaystyle \frac{\sqrt{2}}{2}

$\displaystyle - \frac{\sqrt{2}}{2}$\displaystyle - \frac{\sqrt{2}}{2}

$2\sqrt{2}$2\sqrt{2}