a/ \( (P):y=-\dfrac{x^2}{4}\\\begin{array}{|c|c|c|}\hline x&-2&-1&0&1&2\\\hline y&-1&-\dfrac{1}{4}&0&-\dfrac{1}{4}&-1\\\hline\end{array}\\\to Ham\,\,so\,\,di\,\,qua\,\,diem\,\ (-2;-1);(-1;-\dfrac{1}{4});(0;0);(1;-\dfrac{1}{4});(2;-1)\\ (D):y=\dfrac{x}{2}-2\\\begin{array}{|c|c|c|}\hline x&-2&-1&0&1&2\\\hline y&-3&-\dfrac{5}{2}&-2&-\dfrac{3}{2}&-1\\\hline\end{array}\\\to Ham\,\,so\,\,di\,\,qua\,\, (-2;-3);(-1;-\dfrac{5}{2});(0;-2);(1;-\dfrac{3}{2});(2;-1)\)
b/ \((d)//(D)\\\to \begin{cases}m+2=\dfrac{1}{2}\\-m-3\ne-2\end{cases}\\↔\begin{cases}m=-\dfrac{3}{2}\\m\ne -1\end{cases}\\\to m=-\dfrac{3}{2}\)