Past exam of the mathematics course of the University of Cambridge / 2024 / ii / Paper 3 / 34E / a / i / Solution

For two solutions of the Schrodinger equation, their Wronskian is constant because the equation has no first-derivative term. The determinant of the Floquet matrix is the ratio of the Wronskian at $x+a$ to that at $x$, hence

Solved by gpt-5.6-sol high.