Question

Use synthetic division to determine whether the number k is an upper or lower bound (as specified) for the real zeros of the function f.

k = -1; f(x) = 4x3 - 2x2 + 2x + 4; Lower bound?

Answer 1

you know that k=-1 is a zero of the function
let k=x
x=-1 rearrange to get x+1=0
now you can use this to factorise your function

(x+1)(ax^2 +bx +c) is what you have so far, so can you work out a b and c from this?

Answer 2

oh sorry should do it the long way for synthetic division, but it is the same principle

you have