a. increases on $(-\infty,1)$; decreases on $(1,\infty)$ b. maximum $(1,7)$
Work Step by Step
a. Using various $t$ values, we can graph the parametric equations as shown in the figure. We can identify that the function increases over $(-\infty,1)$ and decreases over $(1,\infty)$. b. We can find the vertex at $(1,7)$, which gives a maximum at $x=1$ with the value $y=7$.