$\text{a)}\left\{\left(-3,1\right),\left(-2,0\right),\left(-1,4\right),\left(1,1\right),\left(2,4\right)\right\}$  

$\text{b)}\left\{\left(-5,1\right),\left(-4,1\right),\left(-3,1\right),\left(-2,0\right),\left(0,-1\right),\left(2,-2\right),\left(3,-2\right),\left(4,-2\right)\right\}$