Answer:
y=-(x+3)(x+1)(x-2)=-x^3-2x^2+5x+6
Explanation:
If the zeros are:
x1=-3
x2=-1
x3=2
then the function is:
y = a (x-x1) (x-x2) (x-x3) = a (x+3) (x+1) (x-2)
y = a (x^3+2x^2-5x-6)
To find the value for "a" we use the information that, if x=1, then y=8:
y = a (1+2-5-6) = a (-8) = 8 therefore a=-1
So:
y=-(x+3)(x+1)(x-2)=-x^3-2x^2+5x+6