Note that the vertical and horizontal scales are not the sam

(Note that the vertical and horizontal scales are not the same.) Find the equation for a cubic polynomial that could generate this graph given that it passes through the point (0?4).

y=

Solution

the roots are -2,-a,1 equation is (x+2)(x+a)(x-1) at x=0 y=-4 =>-2a=-4 =>a=2 equation is (x2+4x+4)(x-1) =x3+3x2-4