I don't think it breaks trust, if you tell them what's going on. "Hey kids, I'm going to give you a problem that went unsolved until Newton. I don't expect you

I don't think it breaks trust, if you tell them what's going on. "Hey kids, I'm going to give you a problem that went unsolved until Newton. I don't expect you to find his answer, which I'll teach you later, but I want you to try to solve it your own way."