1. The problem statement, all variables and given/known data If y=f(u) and u=g(x) f and g are differentiable; show that d^2y/dx^2=d^2y/dx^2(du/dx)^2+dy/du(d^2u/dx^2) 2. Relevant equations f'(x)=df/dx 3. The attempt at a solution I think the notation is throwing me off, can this be translated in prime notation? And I know y is a compostion of f and g.