Consider the operator Qhat = d2/dϕ2, where (as in Example 3.1 in Griffiths) ϕ is the azimuthan angle in polar coordinates, and we are working with functions f(ϕ) on the finite interval 0 → 2π, and f(ϕ +2π) = f(ϕ). Is Qhat Hermitian? (i.e. Show that < f | Qhatg > = .) Write out with integrals what you are trying to show is true, if it is Hermitian. (Spoiler: it is.) You will use integration by parts, but you can avoid actually fully completing the integral (which is difficult to do, since you don’t know what functions f and g are!)