For all $f \in E$, we set, $$\forall s \in [0,1], \quad T(f)(s) = \int_0^1 k_s(t) f(t)\,\mathrm{d}t$$ Let $\lambda \in \mathbb{R}$ be a nonzero eigenvalue of $T$ and $f$ be an associated eigenvector. Show that $f$ is a solution of the differential equation $\lambda f'' = -f$.
For all $f \in E$, we set,
$$\forall s \in [0,1], \quad T(f)(s) = \int_0^1 k_s(t) f(t)\,\mathrm{d}t$$
Let $\lambda \in \mathbb{R}$ be a nonzero eigenvalue of $T$ and $f$ be an associated eigenvector. Show that $f$ is a solution of the differential equation $\lambda f'' = -f$.