Recent content by steve B. 98

Homework Statement A cylindrical rod of length w carries a current I as shown(perpendicular to B) and is bathed in a field B perpendicular to the plane in which is a " shaped rail. The rod rolls without slipping on the rails, its length perpendicular to the two parallel rails and equal to the...

I'm trying to solve this problem from a high school math competition: Find all functions f : R → R such that, f(f(x+y)-f(x-y))=xy, for all real x,y. Any ideas of how to approach it. I have found that f(0)=0, if x=y f(f(2x))=x^2