The Graph Of $f ( x ) = 2 x ^ { 3 } - 3 x ^ { 2 } - 12 x - 5$

The graph of $f ( x ) = 2 x ^ { 3 } - 3 x ^ { 2 } - 12 x - 5$ is concave down for $x < \frac { 1 } { 2 }$ .