Which condition must be satisfied for the potential energy in an SHM system to be expressible as a quadratic function of
Potential energy in SHM ( U = 1/2 k x² ) is quadratic when the force is conservative and linear ( F = -kx ), distinguishing SHM from non-linear systems.
Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Electric Charges and Fields and Electrostatic Potential, Topic: Electric field, potential and capacitance concepts.