Exercise 23

For a certain function $g$, $\fe{\fd{g}}{t}=-8$ at all values of $t$ on $\ointerval{-\infty}{-3}$ and $\fe{\fd{g}}{t}=2$ at all values of $t$ on $\ointerval{-3}{\infty}$.

Lisa thinks that the graph of $\sd{g}$ is the line $y=0$ but Janice disagrees. Who's right?