1. The problem statement, all variables and given/known data http://i.minus.com/iCJwlfzPc5fRu.png [Broken] 2. Relevant equations This feels like a movie requiring the suspension of disbelief. 3. The attempt at a solution cot(x) = cos(x)/sin(x). cot(0) = 1/0 Right? How in the world then is 0cot(0) - 1 = 0? That should be infinity minus 1.