grandes-ecoles 2014 QIII.C.4

grandes-ecoles · France · centrale-maths1__psi Differential equations Eigenvalue Problems and Operator-Based DEs
We assume $\alpha = 1$ and use the notation $V_n(z) = U_{n+1}(z,-1)$, and $$\varphi_1(y) : t \mapsto \left(1-t^2\right)y''(t) - 3t\,y'(t)$$ By differentiating twice the function $t \mapsto (\sin t)\,V_n(\cos t) - \sin((n+1)t)$, show that for all $n \in \mathbb{N}$, $V_n$ is an eigenvector of $\varphi_1$.
We assume $\alpha = 1$ and use the notation $V_n(z) = U_{n+1}(z,-1)$, and
$$\varphi_1(y) : t \mapsto \left(1-t^2\right)y''(t) - 3t\,y'(t)$$
By differentiating twice the function $t \mapsto (\sin t)\,V_n(\cos t) - \sin((n+1)t)$, show that for all $n \in \mathbb{N}$, $V_n$ is an eigenvector of $\varphi_1$.