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

I believe that it is lower bound, is that correct? How would I solve this?

Answer 1

Possible zeros:
\[\pm\frac{4}{1},\pm\frac{4}{2},\pm\frac{2}{1},\pm\frac{2}{2}, \pm\frac{1}{1},\pm\frac{1}{2}\]
or:
\[\pm4, \pm2, \pm1, \pm\frac{1}{2}\]

Answer 2

\[f(x)=2(x^2+2x^2+x-2)=0\]
\[x^3+2x^2+x-2=0\]