1. The problem statement, all variables and given/known data So I'm doing problems where I have to verify Rolle's hypotheses. I am only having trouble with the differentiability part. My professor wants me to prove this. So for example, f(x)=√(x)-(1/3)x [0,9] 2. Relevant equations none 3. The attempt at a solution 1.) I know the function is continuous because root functions are continuous on their domains and polynomials are continuous everywhere therefore the difference of two continuous functions is continuous. 2.) What could I say about it being differentiable? My GUESS: it is defined everywhere on its domain [0,9] and continuous it is therefore differentiable on its domain [0,9]? I am only stuck on 2.) so no need to go further on the problem.