MIT OpenCourseWare uses French as a reference, but provides free, complete lecture notes covering the exact same material:
Using a digital copy of AP French’s work offers several advantages for modern students: a p french vibrations and waves pdf
💡 When working through the problems, remember that the "physics" happens in setting up the differential equation. The rest is just calculus. MIT OpenCourseWare uses French as a reference, but
Because this is an older, classic academic text, it is widely available, but you must be mindful of copyright status depending on your region. but provides free
It is known for taking students from the specific case of a simple harmonic oscillator to the general complexities of wave propagation with crystal-clear mathematical reasoning. It avoids "plug-and-chug" formulas, focusing instead on the why and how of the physics.