One of the first calculus class problems is the sliding ladder. In this problem, a ladder is resting against a wall when, all of a sudden, it starts sliding down! In this problem you're solving for dx/dt or the rate at which the point B is moving away from the wall (point C).
Input constraints:
-The rate of slide must be negative for the ladder to slide down
-The initial height of the ladder must be less than the ladders length

**Tags: Ladder, Calculus, Derivatives, Pythagorean-Theorem**