30 the change in water level of a lake is modeled by a polynomial function, w(x). describe how to find the x-intercepts of w(x) and how to construct a rough graph of w(x) so that the parks department can predict when there will be no change in the water level. you may create a sample polynomial of degree 3 or higher to use in your explanations.

F(x)=f(x)=x3+2x2−x−2
0=x3+2x2−x−2
0=(1)3+2(1)2−(1)−2  −−>  1+2−1−2  −−>  =0, so   1  works.
0=(−1+2(−1−1)−2   −>  −1+2+1−2  −>0   −−>   so,  
f(x)=(−2)3+2(−2)2−(−2)−2   −>  −8+8+2−2   −> 0   So,  −2  also  works.
make x=0
f(x)=(0)3+2(0)2−(0)−2  ⇒  0+0−0−2  ⇒  −2.   So  y−intercept  is   −2
the x-intercepts are 1, -1 & -2 OR (1,0) (-1,0) (-2,0) and y intercept is -2 OR (0,-2) then you can graph it.