If $s$ is an integer and the root(s) of the quadratic expression $\frac{1}{2}x^2+sx-\frac{1}{2}$ are integers, find the sum of all possible values of $s$.
\($\frac{1}{2}x^2+sx-\frac{1}{2}$\)
The sum of the roots is -s / (1/2) = -2s
And the product of the roots is (-1/2) / (1/2) = -1 (2)
If the roots are integers then, by (2), one must be -1 and the other is 1
So... s must be 0
