Answer:
f(x) = ( x + 1 ) ( x - 8 )
Step-by-step explanation:
We have to find a polynomial equation that has double zeros at x = - 1 and at x = 8
Therefore, the polynomial has only two roots and it will be a quadratic polynomial and it has factors ( x + 1 ) and ( x - 8 )
So, the polynomial is y = f(x) = ( x + 1 ) ( x - 8 ) (Answer)
