Question

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 to be used in your explanations.

Answer 1

The polynomial y (water level)
= (x-1)(x+1)
y = 0 at x =1

x=0 y=-1 lake level drops 1 inch when no rain

x=1 y=0 1 inch of rain and water level donot change

x=2 y = 3 2 inches of rain and water level rise up 3 inch