The graph of the polynomial function is represented in the attached diagram.
1) Zeroes:
P(x)=0 when
2) y-intercept:
when x=0, then

Thus, y-intercept is at point (0,0).
3) Minima and maxima points:
- minima - (0,0);
- maxima - (-1.05,3.03) and (1.43,6.83)