Answer
a.
x-intercepts: 0 and 4.5
y-intercept: 0
b.
$(0, 0)$ is a local maximum,
$(3, -3)$ is a local minimum.
Work Step by Step
a.
The graph intersects the x-axis at (0,0) and (4.5,0)
(x-intercepts: 0 and 4.5)
The graph intersects the y-axis at (0,0).
(y-intercept: 0)
b.
Local maxima/minima are found when there exists a rectangle
for which there is one point with greatest/least function values (within that rectangle).
(0, 0) is a local maximum,
(surrounding points have smaller function values).
(3, -3) is a local minimum,
(surrounding points have greater function values).