Answer
$f(x)$ is concave up for all x ($-\infty < x < \infty$)
Work Step by Step
$f(x) = x^2 - x - 2$
1.) Find $f''(x)$
$f'(x) = 2x - 1$
$f''(x) = 2$
Since $f''(x) > 0$ for $-\infty < x < \infty$, $f(x)$ is concave up for $-\infty < x < \infty$.
