A student goes crabbing after math class. He drops the crab cage, and waits. Let $f(t)$ denote the distance a crab is from the cage at any time $t$. Assume $f(t) = -2t^2 - 7t + 15$, where $t$ is measured in hours, and $f(t)$ is in feet. When $t = 1$, is the crab moving towards or away from the cage?
The crab is moving towards the cage.
The crab is moving away from the cage.
The crab is not moving.
There is not enough information to determine whether the crab is moving towards or away from the cage.