So here are 2 questions that are connected in some way. In the past 12 years, no one has been able to solve both of them. Both are NOT trick questions, but they seem more difficult than they look.
Let f(x) be continuous and differentiable function for all x.
1. If f(3) = 5, find f'(x) *HINT* No limits are involved in figuring out the solution
2. Differentiate both sides of the equation f(3) = 5
1. Well I claimed (-infinity, +infinity) after thinking about the possibilities. The teacher told me I was on the right track but I needed more so I think the solution is more complete or I'm missing something.
2. For the second one, I had (-infinity, +infinity) for the left side and then 0 on the right side. This made no sense to me, the teacher said I was so close yet so far away from the solution.